Eye dominance can change, but it usually does not. If you want to start him on a bolt action, get it with the bolt on the correct side. If using a backwards gun were a good idea, all right eyed shooters would have LH guns. People come up with ways to rationalize why they use a backwards gun, but it comes down to laziness or stupidity. You can go buy a LH bolt action of pretty much any flavor you want.
Alternatively, you can go ambidextrous. Lever actions work well. There are semi-auto that have tang safeties or trigger guard safeties which can be switched to the correct direction. AR-style rimfires can usually accept an ambidextrous safety as well. Direction of ejection doesn't bother most people.
Alternatively, you can go ambidextrous. Lever actions work well. There are semi-auto that have tang safeties or trigger guard safeties which can be switched to the correct direction. AR-style rimfires can usually accept an ambidextrous safety as well. Direction of ejection doesn't bother most people.