I'm completely unsurprised by this. Given how huge they are, I'm especially surprised by how few people outside of the /mlp/sphere know about the Mandopony and Blackgryph0n allegations. Both of them had very creepy relationships with Michelle Crebor and Claire Corlett, both of which voice cutie mark crusader (child) characters in the show.
If any fellow Kiwi's want a pit of depraved autism to look into, you can go to any remotely popular /mlp/ general and visit their Discord servers for a look around. Even if it isn't listed in the OP, just ask in-thread for the Discord link (they all have one). They are literally packed with open paedophiles and foalcon artwork (the horsefucker toddlercon stuff), and this shit runs all the way to the top of a lot of these places. Most 4chan /mlp/ general servers are owned and moderated by the same small tight-knit group of (in some cases, literal) tranny janny's who all know each other and worm themselves into head positions over time. The whole situation is really weird, and a brony I know was telling me about how big of a problem it is in the giant invite-only /mlp/ drawfag server especially. The entire fandom has a problem with these sorts of people, but now the fandom has almost died, nobody gives enough of a shit to weed them out and they're just left to do whatever they like.