I can’t speak specifically to UMD so I hope you don’t mind the generalities.
Is there a possibility of your son switching dorms for second semester to one with a kitchen facility? IMO, the transition to off campus is a big one in terms of responsibilities and for a freshman, I like the idea of them still living on campus as they grow their community and have more time to mature.
I would recommend having a doctor’s note about the weight loss and the allergy when approaching the residence life people to request either a change in location, or the breaking of the dorm agreement (which is for the full academic year).
If I’m remembering correctly from when my daughter toured and was accepted, there is no on campus residency requirement for honors so that shouldn’t be an issue (although the rules could have changed between then and now).
Both my H and I, and our D all lived off campus for part of undergrad. My D lived off campus for 1 1/2 years (1/2 year because of co-op) and had a great experience but she had already lived independently two summers for internships and co-op so wasn’t trying to figure out cooking, shopping, cleaning, bill paying from scratch. I actually think living off campus at least for a little bit is a good stepping stone to adulting. I just wouldn’t necessarily recommend it for a freshman.
I hope this works out for your son! The weight loss is concerning 