Why would Greene's past keep him from winning the Olympia, considering that:
a) We already had a gay Mr. Olympia over 30 years ago (Dickerson)
b) IFBB has long since waived the no-nudity clause; once it suspended Erika Mes just for posing naked. Since then, we got IFBB female pros doing straight-up porn (i.e. Denise Masino, Gayle Moher, etc.) without so much as the league batting an eye. MuscleMag used to advertise this stuff for years, long before Greene even turned pro.
Dickerson was quietly and respectfully gay, and there was no internet. He did Colt magazine shoots, but you had to really look for them. With Kai, the Grapefruit thing is right up front, and the under towel gif is just under that. You can have a Gay Mr. Olympia, you can probably do artsy pictures now, but the hardcore bizarre gay for pay won't fly for the face of bodybuilding.
You've got old men running the boards of these companies that might consider it a blow to supplement sales, etc.... The Olympia isn't about bodybuilding, it's about marketing, sales, and promotion of supplements on the back end. You can't risk the mainstream getting a full on look at all the prostitution, etc.... that is inherent to bodybuilding right up front like you do with Kai, they have to be slowly broken in like we were

.
As for female bodybuilding, those girls aren't winning the big show, The Olympia. And to be honest no one gives a shit about Female bodybuilding, except for schmoes, and they are their own little sub class.
Kai will never be Olympia.