Williams accused umpire Carlos Ramos of sexism after she was given three code violations during the U.S. Open final in September.
The commentator is steeped in more controversy.
McEnroe has already been in trouble for comments he made this summer.
The SW19 champion shared a joint with The Rolling Stones' frontman.
This is Murray's first Grand Slam as world number one.
Murray, the French Open runner-up, has been linked with a return to former coach Lendl.