Will my boyfriend remain on probation if he violated probation?

Retain a good criminal lawyer as that is a serious violation of probation and he might get a jail term of a year, a few months, or longer if it was a felony probation.

PO makes a recommendation. Court decides.

That is up to the probation officer and the judge.

Like many of the questions here, this cannot be completely answered; to answer it properly, one would need more information. It is possible that your boyfriend will not be sent to jail and, the judge will simply continue his probation. This depends on numerous factors, including, but not limited to: Where is this (some courts are more lenient that others)? Has he completed any, some, or most of the classes, community service, etc.? Does he have any good excuses for not having completed the required classes? Why didn't he appear (once again, he will need a very good excuse)? Any one of these factors could change the outcome. Additionally, there are other factors that could affect the outcome as well.

The probation officer can only make recommendations to the court; the judge is the one who has the final decision on what sentence to give. They could continue him on probation and either extend his probation, add to his conditions, or give him some jail time. They can also revoke his probation and then he could be resentenced up to the maximum for the original offense. He could also be in danger of losing any deferred sentencing status that he had as well if he was given that. Each judge handles these matters differently and it will also matter if he has ever had any previous violations or not. He should seek out and retain an experienced criminal attorney in his area that handles probation violations because this could have serious consequences.

Having probation reinstated is a good possibility, but it will be up to the judge and the recommendation of his probation officer.