OK let me make sure I got this straight - the college cannot change the unofficial visit due to academic reasons? I've never heard of this but could be possible I guess.
Before we got any further the 10 million dollar question is what has the HS coach said about him possibly missing this non-conference / whatever game?
Overall as a head coach I would wish him luck as he visited the school and welcome him back with open arms at the next practice / game. This is part of our job to help them get into college either as a student and / or athlete. Now if it happens all the time (or trying to) then we need to have a talk about how to schedule these things. I've never seen a school not understand or work with a HS kid with their games. But I also don't know all the details so more info would be helpful.