> Importantly though they don't use the in-game chat, they fire up a group voice call on messenger

My 15 year old does this. I thought it was interesting, he and his friends just start a call, put it on speaker, and then talk to each other while gaming.

My youngest (now 13) played a lot of Roblox when he was younger but lost interest. We’ve talked a lot about the risks and how robux is a scam, he’s even run across “gooners” in game. It reminds me of hanging out at the mall with my friends when I was his age. Plenty of risk there and you need to know how to deal with it. I remember once being offered a ride home by a stranger, the total child kidnapping stereotype, I just said something like “is this a joke?” and they took off.