The answer to this is very simple. Honda is scared shitless of Cyborg, especially if the fight takes place anywhere above 135. It has nothing to do with Cyborg getting popped and being a "cheat". Cyborg could fight 10 more times and test clean each time and there is still no way Rousey takes the risk of fighting her above 135. I'll be surprised if she will fight her at 135. My guess is that if Cyborg manages to successfully make it down to 135, Rousey will quickly decide that acting is the place for her instead of MMA.
.......is always looking for new candidates to add to his ignore list. Luckily I'm on Sherdog so they are easy to find.