Can you recall any time R* have done that? Say what you like about GTA V, it wasn't undercooked. GTA Online was a mess, even after releasing it a month later than the single player. Pre-release, their focus was clearly on single player.
Did you notice the power of Rockstar's marketing? Other game companies are using Rockstars promotional material to promote their own games. Yep, thats a thing. If they have any sense, they'll know that one bad game destroys any of the mystique they have.
@Quinn I'd be really surprised if their PlayStation Partnership amounts to anything more than a throwaway mission. Sarajevo 6 style. It gets R* on stage at E3 without them even having to go, and Sony gets to be like, "we're friends with Rockstar, we swear"