It’s super cool to see the new mission trailer!
(And Top Gun Maverick’s at almost the same time!)
Here are some guesses of mine.
1. The submarine won’t be destroyed in Operation Sighthound, since it’s too troublesome to make new models, so maybe we’ll fight the submarine for three missions and finally get to sink in in the third mission.
2. The Osean ships won’t make it and will be the first victims of whatever super weapon the submarine is carrying. That’s a routine for AC games.
3. There’s a chance that Trigger can get to fly through the tunnel on the submarine as a challenge.