Do you seriously think Cyborg (not old or retired) would last even a minute against old and retired Randy?
Look, Cyborg is great, but the differences between men and women in these sports is huge. Its why Serena Williams lost 6-1 to the 203rd ranked male player (who'd just had a beer). Think about that, the greatest woman's player ever, someone much more athletic and skilled than Cyborg, lost badly to the 203rd male. Its why the national women's hockey team (Olympic gold medalists) play 15-16 year old boys for practice (and lose most of the time even though body checks aren't allowed), why the women's 100m sprint record, a steroid based time from 1988 that no woman has come close to since is regularly beaten by high school boys. If you want to match up Cyborg with a trained male fighter, find a high school boy, that might make it competitive.
The key word is trained; Cyborg would absolutely kill 99% of untrained men. But Mayweather is anything but untrained. She's cannon fodder for Randy, and sadly, almost certainly as well for Mayweather. She had a hard time getting her hands on Holly, who's a turtle in slow motion compared to Mayweather.
If Cyborg really thought she could compete against men she'd be asking for a fight with TJ, or asking MM to come up in weight. She knows better, so she makes comments about someone who she knows she'll never get a fight with. It was pathetic when Rousey did it, and as much as I prefer Cyborg to Rousey, its pathetic when Cyborg does it.