D..
Best to ask the dentist this. I don't think I would worry about this if I were you. They've been doing this for a long time. At least they didn't remove the tooth and you have a space with a hole there, so that he has to eat on the other side of his mouth all the time. Plus, his teeth would all shift and you'd be guaranteed braces.
Talk to the doc about your concerns - he is the expert.
Dawn