Days Gone won't be as big, it just doesn't have the appeal and doesn't look good enough. People have moved on from zombie games and this one doesn't stand out.The bolded is just not true. That's just something gaming forums are trying to convince themselves of.
Infamous didn't sell that much compared to the others either and I can see that being the same for Ghost, Sucker Punch just don't have as big an appeal.
Spiderman will obviously be huge.
Days Gone is pretty much the only Sony first party game, that I've ever heard random people in real life talk about anticipating. Of course that's not scientific or anything, but believe me that game has massive mass market appeal.
Also the counter to your Sucker Punch point would simply be Guerrilla Games.