I'm hoping this isn't Assassin's Creed: WWII. These movies make it look more like Mercs in WW II plus set-pieces like in Gears. Nothing notably quiet in any of that gameplay footage, but I can still hope. More than anything, I'm worried about the "quiet in, loud out" mission gameplay described, as that pattern was worn thin enough with Assassin's Creed.
As I recall, Mercs 2 was developed by a different team in Pandemic than the first one. Maybe it was the Aussie team which had been on Destroy All Humans or something? Mercs 2 is a clusterfuck compared to its predecessor; if they were separate teams, and this is the Mercs 1 team, it may be good.