There is a ton of kids under 13 who have them, my relatives kids have them and they are 13 and under that they use to say hi to their friends and they never had any issue. It seems FB picks and chooses who to ban.
they lied about their age when they created the page. You have to input your birthday when you create your page. I’m 46 so it’s not an issue. The daughter of a former classmate has a page and lied about her age.
Yes, FB can be very arbitrary in who it bans.
But this is a pretty cut/dried violation of their rules, and the kid’s age has been well publicized so there’s no doubt that he’s underage.
Which is a shame, but still it’s their site so their rules do apply.