The word gets a number of hits on Google (not all related to Michael Jordan's clothing line), so in a sense it does exist.
The logo on Michael Jordan's "Flighten Up" line is a basketball player aloft holding a ball.
"Lighten up" is a common idiom said when encouraging someone to worry less, become more cheerful, less sad or discouraged, like lifting the spirits or mood.
Michael Jordan was one of the best basketball players ever to play the game. He had one of the (if not the) highest vertical leaps (almost 48 inches). That's just about like flying to the mere mortals watching the game. That's a lot of "air" beneath him.
In keeping with "Air Jordan" sneakers (a Nike line designed and named for him), intimating that wearing the sneakers might give you a bit of the vertical jump he could achieve (or not), his "Flighten up" is also a play on that concept.
I'm not sure it has anything to do with enlightenment. Just a play on words, and his brand may well not have been the first to make that portmanteau.