The fact that people care so much about this is puzzling to me. It is clearly a prank. And I get that some question his judgment behind the prank. (Personally, I like it). This would seem to be a matter of one's taste for pranks. IMO, it's just Rex being Rex. He is known for this sort of thing. Any other coach ever do a press conference in a wig and insult his sister-in-law? Oh yeah, the Jets were winning then, so it was funny.
Perhaps you can all wait to pass final judgment until his press conference. By the way, Tom Gamble - whom I believe is the leading candidate for the GM job - has known Rex for 20 years.
Gamble worked with Buddy Ryan in Philadelphia and has known Rex Ryan for more than 20 years. So he and Rex, who have a mutual respect for each other, could become a strong team.