I think the next release should be still in WWII. However I'd like to see a arcade/less realistic version with a really nice storyline while still keeping the game dynamic. Ubisoft has already done this with Il-2 and Blazing Angels.
What spawned this idea was seeing the interaction between the captain and crew in SH5. Also a memory from long ago in Aces of the Deep... THE NIGHTCLUB!
Imagine returning from a patrol and speaking with others inside the harbor. Going to the nightclub and having other captains give you hints about things you may encounter on your next patrol. Some unhistorical upgrades for the boat would be cool too
I know it sounds a little rpg'esque for the hardcore simmer out there but personally I love RPG's and I'd like to see the two come together.