I have seen this script played several times, already. When Pete Caroll coached the Pats, his DC was a innovative blitzer. It worked too; for about half to three quarters of a season. By then all had been seen on tape and every OC had poured over every Blitz and instructed the players on a counter. Pete's Defenses then collapsed,when the Blitzes didn't work near as well.
Just like I expect Jabba Wreck's to do, as well. If you remember his daddy, Buddy, had created the fantastic 46 blitzing Defense of the '85 Bears. The Bears had infinitely more talented players than these Jets, but the 46 only lasted for two years, before everyone caught up with it.
It's been more than 2 years that Rex has been fielding a dominant defense. He was doing the same thing with the Ravens for some time before he did it with the Jets. And to be the number one defense in his firt year is not a fluke or something that tends to collapse. The guy is a defensive genius. If you want to count on anything collapsing, you'd have more of a betting chance on the offense, with either Greene getting hurt (injury prone), Sanchez leading the league in INT's (again), or Holmes Edwards and LT never reaching their potential as Jets.