I’m not sure about UCR but I am somewhat aware of what is happening at the other two campuses.
UC Davis has housing for freshmen (mostly triples) and for sophomores in university owned apartments (West Village). I have not heard of freshmen or sophomores who wanted university owned housing that were not offered it.
UC Irvine has been less organized. They just notified freshmen of dorm assignments and move in dates two days ago. Many sophomores applied for housing in ACC but were told in July that it wasn’t likely so started looking for apartments in town. Apparently ACC is notifying students who already signed leases elsewhere that spots are now opening.