I think Dana will never do cross promotion fights. UFC has been in business for tens years, and Dana only allowed Chuck Liddell to fight in Pride once (other promotion), Conor McGregor to have a boxing fight against Mayweather (boxer), James Toney (boxer) to fight against Randy Couture under mma rules and wrestler (the one that is a fake theatre) CM Punk fought 2 times unsuccessfully in UFC. That is it. Only 5 unusual behaviour or allowance from Dana during whole UFC life.