I feel confident in saying that ROTR would have done better if Uncharted 4 was coming out now instead of March. Not being able to co-op the UC4 hype and champion itself as the XB1 alternative killed their potential hype train. It just felt like no one cared this game was coming out, including MS and Squeenix.
Publishers have tried to piggyback off more popular franchises before and I don't think it's ever worked out that well. Exclusive or not, people usually don't settle for second best.
If anything, I think Uncharted 4 coming out this holiday season would've sold even less Xbone's and made it even more obvious where the fanbase for those kind of games is.