They don't know what was happening to his body, his symptoms were severe, they don't know when these sudden libido will surge or when he'll start to secrete the pheromones which will attract the others sexually, leading to more chaos and troubles. So it's better to stay cooped up in your own comfort rather than be uncomfortable around others and live in fear during that week.
Those boys are budding teenagers who are just learning what is what about abo without any guidance, no matter how mature they behave, at the end of the day, they're still teenagers who don't know anything, so I think you can complain about the situation that much or really find any fault.
Fr and the guy is like the son of a doctor. He was probably worried the omega would be taken in for experiments or something. Better to stay hidden than get caught
I think it’s kinda messed up that the Omega was just expected to stay secluded in the school storage shed just because he had the more severe symptoms. The Alpha went back home, to class, got them clothes, etc. meanwhile his mate was cooped up in an uninsulated area cluttered with equipment for an unspecified amount of time.