I think GSP is already too far away removed from his prime at this point. Maybe it was the weight but he looked slow against Bisping and that was 2 years ago. Khabib would smash him.
The weight factor, the implications that kind of inflation would have physically, the layoff.. there's a million possibilities, of course. Cant really be that far removed to have dominated the MW champ at the time though, considering Left Hook Larry was still actively competing at that time which cant be discredited, regardless of the fighter ability. Idk, I think it can go one of two ways; either the weight cut proves to be too much for him to physically handle and will underperform simply through depletion alone ie power transfer & explosiveness, but if he can log the weight back up in equation to Khabib's "on-the-night" weight then it's a very dangerous situation for the Rooshan man that night. It's not really up for debate that GSP's stand up is literally eons beyond Khabib's either, so there's that to factor in too. Won't be a domination by Khabib in any scenario though IMO