Really, if he didn't want the fight then why is the rematch going down? Surely he'd find a way to get out of it if that was the case. We all know Bhop is a slow starter and regardless of how Dawson looked in those two rounds, anything could have happened had this match stretched on.
It depends on who's doing the time traveling. If Lamotta goes into the future, Arum won't make the fight happen until the effects of time travel get to Jake's body. If Pacquiao goes back into the past, he won't perform as well due to the fact that he'll miss his family, friends and country of his era, gravely effecting his focus.