This is a genuine question and I know it might sound choosing-beggary:
is it a lot of work to implement the next school program? Compare to bigger updates that require new mechanisms and content, I think just put up new courses for player to enroll after they finish first year is not that complicate, right? You can reuse everything else from first year.
It will make sense to put this behind other items on the road map if the sophomore and junior year life is a completely different play mode. Is the time advancement a key plot?