Until it happens it's not even worth entertaining the idea. Rumors so far that's it... Boss denied it too..
If it did happen - New UFC ownership might push the UFC to even new heights.. If investors are willing to pay 4 billion I'm sure they will do their very best to keep building up the UFC machine world wide.. UFC and MMA is still a growing sport, probably not a bad investment even for that price..
If I were Dana White and the brothers I'd sell it for 4 billion and sail off into the sunset.. Who needs all the headaches? Fighters canceling fights, diva's like Conor McGregor making demands, etc.. etc..