The “we estimated your age from account signals” bit is the polite version. Australia made the big platforms do this in December, and the regulator’s first report found some of them letting under-16s retry the age check until they passed. So the kids get infinite continues and the adults get checked too.

France tried to ban social media for under-15s this summer and its Constitutional Council struck it down for exactly that reason: to check the kids you have to check everyone, and the law had no privacy guarantees for the adults. Discord just skipped the court part.