From what they've said it sorta is that? The SP is linear stuff like this and all the GAAS takes place in open world zones that have their own storyline.I still dont see how this game is going to work as a GAAS style game without it feeling tacked on. This would have been just fine as a Spider-man PS4 type game, with coop.
It's a weird way of doing it, kinda feels like even if they're successful they'll end up with two different playerbases.
Also I really hate that we use "GAAS" as a replacement for "Online ARPG"