I was fortunate, when my kids went through this, that we had friends who would advise us to “always do the housing deposit”.
The school deposit you can do by the deadline.
The housing deposit is a completely different thing. There’s a difference in rooms and how fast they run out of those rooms. At my daughters school, they had a lottery system. You needed to get a high number (1-50 vs. #362) to get into the really nice buildings but if you didn’t make a housing deposit, or you waited on it, your numbers were lower(#501). Some schools can’t guarantee freshman housing if you don’t make the housing deposit by the deadline. You really have to check with whatever school you’ve applied to and accepted.