The two main bones of contention seem to be the fact that the game only offers the VII sub, and the fact that the game ends in 1943.
The second of those two is obviously modable based on Dan's answer to Neal in the interview....
Dan: In the game, the way the game will be launched, there won't be any way to be able to continue the campaign past 1943, but there is nothing stopping the modders from keep adding more content, which comes afterwards. There's no hardcore limit for how far you can play in the world, it's just how far OUR campaign goes.
Seeing what lurker was able to do with Silent Hunter IV 1.5, extending this game to 1945 must be more than doable with the modding talent we have here.
As for adding additional subs to the game, I would like for an experienced modder to tell us if this will be feasible or not.....if they know at this stage. Personally, I love the VII and I always choose that sub when available as an option. So, if we can extend the game to 1945 in a VII sub, I'm a happy camper.