Short answer is no
If the Soldier asks for deletion of orders, he or she will keep the bonus. Most bonuses are paid based on MOS/Skill Level and sometimes ASIs or SQIs. The only time a bonus is taken back for deleting PCS orders is if the Soldier receives a location bonus (this is likely not the case as we have not had a Korea location bonus for nearly a decade).
On another note, I strongly recommend this Soldier gets in contact with their Career Counselor ASAP. When orders generated by reenlistment are interrupted by a deployment, retention branch is required to honor those orders. The Career Counselor can move the report date fairly easily, and in most cases the orders don’t change if the report date is only moved a month or two. In some cases, if the report date is moved far enough, the pinpoint orders may change (i.e., Soldier gets a 7 month deferment and the slot they were expected to fill ends up being taken by someone else), but the assignment guaranteed in the contract is still honored. In any case, if the Soldier wants to completely delete the assignment, they need to submit a waiver of reenlistment option and also submit a 4187 requesting a deletion of orders to retention branch.