Alternative playstyles should definitely be the focus here. They should also take some time to examine some of the more famous successors of snowflake chapters, since just because the Knights of Blood have Baal predators doesn't mean that they're going to fight just like their progenitor, and just because the Consecrators have a cargo ship full of relics doesn't mean they shouldn't have a chapter master*.
It could also be a place for them to explore different, for lack of a better term, formations within an established chapter so that it doesn't clutter the parent codex. Put some new things in for different great companies, maybe something on tyrannic war vets for the people complaining that Ultramarines don't get enough content. I dunno, honestly this just seems like the perfect place to put basically any niche new marine content out so that marines don't clutter the main release schedule more than they already do.
* This is a big one since RAW
the DA codex states specifically that you can use successor chapters in the book but if you do you don't get to use named characters, and while you can build your own normal and terminators company masters, there's no DIY
option for chapter masters or bike masters. I game with a friendly group who doesn't care but I have heard of people encountering issues with that before. Also, it would just be kind of nice to be able to have a chapter master with a load out other than combiplasma/big sword.
Edited by FlamingDeth, 21 June 2019 - 06:53 PM.