I don't think he changed his name. He is referred to by his friends as Jordan or JC, so I'm pretty sure he is still Jordan Chandler. Actually all the family are Chandlers which I always found a bit odd. I mean why is Lily Chandler a Chandler? Her father was not Evan but Dave Schwartz. It's odd. June also still uses the Chandler name. Emmanuelle and Nick too, even though they were raised by another guy and they were not on good terms with Evan. Heck, Evan's second wife, Nathalie too still uses the Chandler name, even though she married this other guy (although they are not married any more either). Just odd. But it also means that not only they do not have to go into hiding and change their names because of "crazy fans", but they actually keep using that name even when they actually are not a Chandler any more...
BTW, this guy we talk about - the one who raised Emanuelle and Nick and who made nice remarks about MJ and followed that Venezuelan MJ fan club - is a screenwriter. Not a big one, he's had like two-three D-list movies and documentaries, nothing big. And he's now working on a novel. According to his website it's about a record label that gets destroyed by the Internet and to save themselves they decide to kill their biggest rock star with an overdose of Viagra to generate publicity and interest and sell more records. I'm sure any similarity with MJ-Sony conspiracy theories is pure coincidence. LOL.
Back in the 80s he also had a synth-pop band and the achieved minor success with one of their songs.