True. The balance of the sentence will likely be played out as probation.
Which means that any further violations while on probation will send them back to the slammer.
On the other hand, has anyone looked at the caseload of probation officers in this country lately? Ooof. In PA, they're lucky if they can make appointments to see all their people, let alone track them effectively. (Speaking as someone who deals with the Youth Probation people in two counties...)