@Ghost Before we get into this, let me reiterate something to make sure my most important point is made abundantly clear. I detest the idea of simulated child sexual interactions. I detest the idea of adults playing children engaged in sexual activity with other adults - regardless as to whether those adults are playing adults or children.
So we can absolutely agree, wholeheartedly, that it's creepy as fuck.
That out of the way, paedophilia is as you have stated defined as involving pre-pubertal children. Not other adults. So, assuming that all players involved are adults or that there is a reasonable expectation that all players involved are adults, it's not paedophilia. It's a weird fuckin' thing, but it's not paedophilia. Just as rape fantasies, that also happen all the time on sex games as well as in real life, don't mean the fantasiser is a rapist or potential rapist.
Secondly, my main problem with this entire conversation - especially your parts of it - is that it is bluster. If you want to do something about it, like reporting it to law enforcement, or internet watchdogs, or whomever... do so. We're not the MUing police. Not by a long fuckin' shot. We don't have authority, or impact, or influence enough to just decide "Okay, MUing is banning this thing now."
Thirdly, this entire conversation needs to stop. You need to go take a break, write emails or call who you need to call, because us chatting about it isn't going to change anything. Literally ever.