I know there are def other non-scholars students living in Cambridge Community, so your son is def not alone/unique in that respect! Certainly, if they have Cambridge Community events, then that would be open to all Cambridge Community residents, including your son, so no worries about that. However, if it is a scholars program-specific event, then the director of that scholars program would not recognize your son as being in her/his program, so I doubt they would allow him to attend that kind of event.
Your son will def love the proximity of the dorm, both to physics classes (read he can sleep in until the last possible minute) and also to Eppley (he can work out on a regular basis if he is so inclined). Come b-ball season, he’s also conveniently close to Xfinity center…and really not far from Byrd/Maryland Stadium for football (sorry, it will always be Byrd to me). Whether or not he’s a big sports fan (and I sure as hell am not - except for Maryland games, of course), he really should make an effort to attend some games, just for the experience. Maryland fans are something to experience/be a part of.