Thats obviously fine to do but it is very much going to have consequences for some kids. My kids spend hours a week playing roblox with their IRL friends. 10 - 15 kids on a group call on speaker phone all logged into the same code laughing and yelling for a couple hours a night. If I was to suddenly tell them that they can't play those games with their friends it would have very real effects on their social life. My kids spend a ton of time outside with friends but to ignore that they also spend time gaming with them is not an option.
Self-hosting a minecraft server is still an option. And tons of customisability there and you aren't turning everything over to a centralised server.