I'm not sure about that, I think if you asked most people if a law around signing teenagers from abroad would impact a lad who plays (at age level) for the nation he's moving to and is a full citizen of that country they'd say of course it doesn't, because that makes no sense.
I for one knew the rule existed but given he was born in the UK and plays for England it never would've occurred to me that he wouldn't be able to be registered, that just seems like a mistake in the rules. He's English, of course he should be able to register to play for an English club at an appropriate age group and the regulation as it was written was clearly never intended to stop a transfer like this.