Interesting question. With policy changes flying it seems like they are backing themselves into a corner on this one. While I don't really care for overcelebration, the Leap is a trademark move. If the league makes it illegal they will look like the biggest jerks in sports. But how can they not?
That's called cherry picking.
We all know it goes on in all aspects of all sports, but this one could be considered right in your face. I for one hope they make an exception for the leap, but is that even possible? Or legal for them to do so? Probably, since they made the rule in the 1st place. If they did make an exception, would other teams be up-in-arms about special treatment?
Like I said, interesting question.