Is Discord actually safe for 12 year olds?

My oldest wants to join his friend group's Discord server. I looked into it and the features seem okay (I can see what server he's on, etc) but I'm not totally clear on how moderation works or if there's predator risk? His friends are all from school so it seems legit but I'd rather not be naive here. Anyone's kids use Discord? What safeguards did you set up?