Looking at the last year, and what we know about the near future, 40k is heading for change both narratively and mechanically. Disclaimer, I am not privy to any insider information so this is my thoughts based on what has happened and what we know so far, trying to fit pieces of the puzzle. This is my speculation and most will probably be incorrect, but I like thinking about this and hearing what other people think.
First up, we know a new edition is coming, and from adepticon, that it would come in time for the next adepticon. That gives us a backstop of late Jan early Feb as tournaments don't incorporate rules released generally 30-60 days prior to the event. We have had the gathering storm series and have had major changes, with Cadia falling and the Eye expanding and a Primarch's return.
We have the release (re-release really) of sisters and custodes. Then Shadow War Armageddon is coming soon, and we have Death Guard and Mortarion confirmed. So what picture is this painting? Well for the last year at least we have not had any major faction releases. Genestealer cult, deathwatch, Imperial Agents, sure, but no major codex had been released in 2016. We got some small fluffy factions and a lot, I mean a lot, of campaign and faction supplements. Traitors Hate, Wrath of Magnus, Curse of the Wulfen, Angels Blade, Traitor legions, Death from the Skies, Angels of Death. Given that 8th is coming in less than a year this makes sense.
No one wants to be the codex that is released right before a new edition, as that tends to be the codex that gets screwed. So it makes sense that GW is shying away from major codex updates and sticking to campaigns and supplements. And we may be getting some clues to what is to come. Though its important to not read too much into it either.
The gathering storm book three has a lot of clues in it though I'm sure more than a few are misdirection. But some are certainly not. The primarchs mentioned are definitely hints at the future. Mortarion is one clue that was mentioned and low and behold it is now confirmed new death guard plastic models and Mortarion himself is coming. Fulgrim is also mentioned in rise of the primarch, and that he has plans for the future involvement with guilliman. Given that it has been a while since slaanesh has seen any major release, I would definitely expect to see Fulgrim, the emperors children and daemons released in the near future as well. The real question will be, will this occur before or after 8th edition. I don't know, that depends a lot on how fast they have models lined up.
The brilliance of having traitor legions already released, all they have to do is release models and perhaps a gathering storm style book to include Mortarion's rules and a special formation and detachment for him and death guard. This could also kick off the next part of the Gathering Storm story line and lead to other releases as well. We know they are coming soon, and with the only other known 40k release so far is Shadow War Armageddon (talons is already out), we could see death guard and the kick off of the next part in the story by the end of April. I also have a feeling that Shadow War is part "we are redoing necromunda" and part playtest of the next editions rules to see how its received and give them time to adjust and make changes.
Shadow war also ties into the hints in rise of the primarch, with Armageddon and a resurgent Ork threat being mentioned, now not going to read too much into this as their are more than a few different warzones mentioned, but with shadow war, and given the fact that both guard and orks are older codexs, along with chaos (daemons+marines) this could be hinting at both getting updates in the near future though probably nothing major till after the edition change. But with the precedent of the gathering storm and campaigns, models are no longer tied solely to codex releases. We could see some new and updated special characters and maybe some units updated as well, as seen in the previous campaigns. With Models not being tied only to codex releases, we can see minor updates without having to wait for a new codex, as we are seeing with death guard and I seriously doubt CSM is getting a new book in the next month or two (unless 8th is that close).
Spread out over a few months, this could also lead to the Emperor's children being released at the end of summer, as again, the models are not tied to a codex release and with really only needing rules for Fulgrim and maybe a new formation or detachment, it won't need to be a huge release and can be either the end or start of the next part in the story following Death Guard.
The big thing I keep going back and forth on, is how soon 8th edition could be. With their current release schedule, and with Adepticon as a back stop, they have time to update emperor's children prior to release of 8th, and makes sense for them to do a chaos cult marine update prior to a new CSM codex, where they can focus on non cult units. To me, I am leaning to 8th being released closer to the end of the year, but who knows could be as soon as june. Will we see a tit for tat release of primarchs, with a loyalist released for every traitor? Probably not, but there is no way that guilliman is the last of the loyalist primarchs, it may just be a bit before another comes back and probably will be a major plotline of 8th edition, but probably won't come sooner.
Lets also not forget the funny troll video GW released regarding the new things coming, the one that had the cardboard box with plastic thunderhawk on it. I laughed and was all "well played GW", and then forge world announces they have sold their last thunderhawk and won't be making it anymore, and now its Trollception, with the troll video actually hinting at the truth of a plastic thunderhawk! An even better well played.
Another thing to mention is the absence of Angron, as he is the only daemon primarch of the cult troops and daemons not mentioned in gathering storm, and I think the silence here is deafening. Khorne Daemonkin did not see new berserkers models, and I think the silence here is to not give away that we may get them in the near future, though my bet on them is an after 8th edition release on that, probably with the new CSM codex when it comes, as there is only so many months left in the year, though they could cram a lot in, they also have Age of Sigmar as well, so that cuts off a lot of space on the calendar as well.
Tyranids are also mentioned, along with necrons, but I think these are just to kind of include all the factions they can in the story, though Tyranids could sorely use an update. Given the codex ages, the next major releases will definitely be Chaos, with most likely Imperial Guard, Orks, and Tyranids following that.
The time line in my head right now, is with April seeing Death guard, and a new story series kicking off, tying possibly into Armageddon for small Ork and Guard releases around June/July, then a final arc kicking off in late August/Sept with Fulgrim leading to 8th Edition. I'm probably totally off, but I'm no longer feeling confident that 8th edition is coming in early summer. I expect will keep getting more like the gathering storm, keep us interested while they get feed back from Shadow War Armageddon (as it really is looking like a playtest of some of the core changes for 8th) before finally releasing the next edition. Age of Sigmar will take up space as well, with most likely some major releases in early summer. Basically this leaves us with 8th either coming really soon, or closer to the end of the year, as that gives time for the Chaos Cult marine releases that are in the works, and to introduce new special characters for factions (as IG have lost a few, and well orks just need something good for once) and set up more of the story.
Will be really interesting to see how this all pans out, and excited to see how the release schedule comes to fruition.
Cadia Stands!
GG