@Renee583 Third-party bookings are not allowed on Airbnb, so it wouldn't be appropriate to make arrangements here on your son's behalf. But aside from that, Airbnb is a terrible platform for a year-long rental; listings are priced way above the market rate for equivalent housing, and Airbnb adds huge fees on top of that. People with a spare room who really just want a stable, long-term housemate are not listing it on Airbnb. Instead, I'd suggest that he check Spareroom.com, Facebook, and student message boards at the university.
And just to make sure prospective housemates recognize that he's a mature adult who can look after himself, try not to get directly involved as a parent. 😉