With no judges and no KOs, what we are looking at is an EVT win. With no KOs that drastically increases Jones Jr chances for winning the event. He can come out of this thing bragging about going the distance with Mike Tyson. I don't see any clear pathways for Iron Mike to claim the event with the exception of Jones quitting on the stool.
They'll take turns flashing half-speed bursts of what they used to be. If either gets wobbled, the other will probably hold on to allow the other to recover, ala the Tyson-Sanders exhibition. I think Tyson will have Roy on the ropes a decent amount and throw some half-assed combinations while Roy shells up. Then in the center of the ring, Roy will throw some jabs, the occasional power punch, but nothing with really bad intentions. I'm expecting it to look like a glorified light sparring session where people have no interest in seeing Mike continue the exhibition farce afterwards.