First off, on the turf issue, make sure your kid has the right type of cleats. Soccer cleats made for real grass are called "FG" (for "firm ground"); soccer cleats made for artificial grass are called "AG" (for "artificial ground"). The stud pattern on FG cleats are more "grippy" and if used on artificial turf may increase the stress on the body and increase the risk of injury. My kid has been playing travel soccer for years and spends countless hours on artificial grass. After many hours of research, I opted for a Puma's "MG" (multi-ground, just to make it more confusing) cleats, which have a much smaller stud pattern.
https://www.unisportstore.com/football-boots/puma-future-7-match-mg-forever-faster-sunset-glowpuma-blacksun-stream-kids/336020/
Anyway, as to your question, it really should be up to your kid. If he wants to go back to rec, let him go back to rec; if he wants to stay in travel, let him stay in travel. He may go back to rec and find that he misses the more intense and more skillful level of play in travel, and he may realize that travel is where he belongs. If not, and if he truly prefers rec soccer, that's where he belongs and there's nothing wrong with that.
I've had kids of mine in both travel and rec; some have always been rec-only players, some have bounced between rec and travel, and some have basically been all-in on travel from a young age. His passion for soccer and desire to play at a more intense level are really the most important factors. Explain the pros/cons to him and let him decide -- on an issue like this, which is supposed to be about fun and recreational activity, it's OK to defer more to the kids than we would in other more important areas of life.