It was fully healed two weeks out, but hampered his training. No living wrestling practice, no kicking till two weeks out, etc. Compare McGregors movement from this fight to the Aldo fight. He was much lighter on his feet in the Aldo fight.
As far as getting takendown at will, not quite 4/7 takedowns and the ones Mendes did land he had to chain wrestle for after the initial shot was stuffed, despite having one of the best explosive counter doubles in the game. You know who never defended a takedown from Mendes, Guida and Nik Lentz, do they have no wrestling chops?
The fact is Mendes is one of the best wrestlers in the sport and will take down just about anyone. Yet, when he did get him down he wasn't able to do much. When he advanced his position in the first McGregor was able to scramble back to his feet, and when Chad went for a choke in the second the same happened. That's good defencive grappling and excellent scrambling skills, he's not an offensive wizard from his back, no doubt, but being offensive from your back is being seen less and less because he it rarely works anymore. There was something like 4 triangle chokes in 2014 in the UFC.