It's not by a long shot. Both Max Payne 3 and L.A. Noire were delivered by Social Club, and you wouldn't get a Steam key unless bought from Steam or it was specifically noted as such on the product's Amazon/Nuuvem/whatever page. But you wouldn't see Steam versions sold on third party sites until after release, and even then that was back in the halcyon days of AmazonTony actually giving a shit about their digital games department, not whoever's in charge now.
What you SHOULD be worried about is how well GTAO's nerdcore is going to work on PC, because the Social Club networking for Max Payne 3 was... messy, to put it generously. I'm buying it for the single player, so whatever, but...