Obviously, the end of the collaboration is a problem. Not seeing new books means that we are going to see the community starved for new blood and effectively stuck in a holding pattern until a new solution appears for those of us that want to game in 40k universe. This could obviously come from several directions.
1. Games Workshop could release its own RPG, as they have before. Given their proclivities I wouldn't rate the odds of it being good as high or the odds of it happening as high.
2. FFG could get the license back at some point and revive the system. This could even be the result of GW going defunct. This would be the ideal. For the most part they were good stewards.
3. The community could make its own thing. This has been tried a few times with some very good looking results, but adoption overall has been difficult and the days of Dark Reign are over. Getting players to dive into a non-official book is always a big ask.
What is the path forward for the holding pattern ?
1. Secure the resources as soon as possible. Books and PDF's aren't being released anymore. There will probably be a big sale very soon. Stock up on everything. The ideal situation is that 40krpg's become very accessible.
2. Keep running games, if you like the systems. Keep bringing in new blood. Keep the vets happy. Keep producing assets. Try to keep things organized.
3. Migrate to https://www.reddit.com/r/40krpg/ and other forums before we get archived. There is no good post-Dark Reign successor with more people than 40krpg it's not as good as the forums by far, but it's populated. The community survives by keeping in touch.