They should never have been encouraged to go to uni in the first place, they were told it would all be fine, this is so wrong, I would cancel the accommodation and do an online course, I will be encouraging my daughter to do an ou degree in a couple of years time
I think that would be a real shame. OU degrees are great if you can't travel or you have other commitments, or you love online studying, but most students do enjoy leaving home and mixing with other similarly aged people. The majority of my students don't want to return home, the 2nd and 3rd years are keen to stay with their households/friends, and come onto campus when they can, they tell me they really value the contact with lecturers. I think it is the first years who are more vulnerable, having not made friends already and having not got the hang of studying. There may have been a rationale for keeping them back from starting til Jan, but I think permanently taking them out of university settings isn't a good idea, it doesn't make sense for schools to be still teaching in person and universities not to do anything for years!
In two years time, this cohort will have almost herd immunity, and most of them are asymptomatic or mildly ill, I've seen it for myself this term, many do not know they have corona til tested through the testing of households.
There's too much individual variation in how individuals cope, to say all should go home or all should stay. A second year in a shared house with friends might not be finding two weeks that bad, a first year in a small room might feel very bad indeed, and it's those students we need to be addressing- and as parents, it might be that getting them to come home after two weeks is the right thing.