Word is the game was a trainwreck and that's why the shift in developer and moving Amy Hennig off of it. Yes it's EA and that could just be their version of events but, if you remember, Uncharted 4 was in a bad way at the time she was forced out/left Naughty Dog also and they managed to right the ship without her. It's not out of the realm of possibility that this isn't just EA being EA and rather them trying to salvage this game, especially after ME:A beingly nearly universally hated. As far as the shift in direction from linear singleplayer to the addition of multiplayer, etc. if they had to retool the game anyway, it's not surprising they'd move that direction.