Does Dana White make any money out of this at all if the fight is boxing? I mean did he made a single cent from Conor vs Mayweather fight?
If he didn't get any money at all and just hoped that Conor fighting Mayweather would get more attention to UFC than it doesn't worth it at all. UFC is already quite known thing and there are really EA sports games based on it (and boxing is not quite popular anymore in gaming) and you are still trying to get exposure for your organization by letting your fighters do whatever you want? I don't think so.
If Khabib goes and fights with Mayweather in a boxing match than I seriously believe Dana should give him a punishment like get the UFC some percentage of the winnings or something. If you sign a contract with some place and than just go do other work there should be consequences.
He obviously made money from the Conor McGregor vs Floyd Mayweather fight, tons of it actually. Conor McGregor is under UFC's contract, so it was a clash of two worlds. Dana White was always there during all negotiation times. The deal was probably split but I don't know the exact %.
In fact Dana White just said that the meet with Floyd Mayweather yesterday. Dana is now saying that Khabib will not fight Floyd in a boxing match, that he is very welcomed on the octagon but he will not let Khabib go to the boxing match. Dana doesn't want to see another big name getting beaten up by a 40 year old boxer so he wants to lure Floyd into the octagon for a massive payday. I hope Floyd is smart enough to know that he has no business there. His job is to bring Khabib into the ring. However if Dana doesn't let Khabib do it, and if Dana has a billion dollar deal for Mayweather at the UFC, then Mayweather may actually go into the octagon because the guy just loves money and a billion dollar deal is a billion dollar deal.