Mechanically the guarantee follows the lease obligation, so if the lease runs to July the guaranteed amount runs to July, whether or not the student is still enrolled. Enrollment is almost never a condition of the lease in student housing, which surprises people. The student leaving school is their problem, not a termination event.
What happens in practice varies. Large operators do pursue guarantors, often through the guarantor's own credit exposure, because a form with no re-let provision leaves them holding an empty bed they can't fill until August. Smaller operators frequently take a buyout, two or three months plus the re-let fee, because litigating against a parent in another state costs more than the balance. Whether a landlord in your state has a duty to mitigate damages by trying to re-let is a state law question and it changes the arithmetic completely, so that's the thing to have local counsel answer before you rely on the form as written.
On the drafting: no re-let provision cuts both ways. It gives you no explicit right to charge a re-let fee and no defined process, which means any mid-term replacement gets handled ad hoc. Most purpose-built operators write in a takeover clause instead, where the departing tenant can find a qualified replacement who assumes the bed, with a fee and a credit standard attached. That's cleaner than a buyout and it's how the bed actually gets refilled in December.
The number I'd want from the seller if you're reviewing a portfolio of these is mid-year departures per hundred beds per year, split between transfers, withdrawals and skips. Transfer rates run materially higher at less selective institutions, and that's a place where the campus quality question and the lease enforcement question turn out to be the same question.
