What happens when you receive a PCS report date during deployment?

The first question is, is he really deployed, or just gone somewhere? When a unit deploys for combat operations a Stop Move code with an end date is placed on the Soldier to prevent this kind of thing from happening.
If he is just away on TDY or training his unit will have to fly him back with enough time to clear, or request a deferment for him.
If he requested the assignment through reenlistment his career counselor can make the adjustment and it's fairly quick, otherwise it's on the human resources section to make the deferment request.

There isn't anything you can do in regards to booking travel, your spouse needs to attend a levy brief, turn in a levy packet, and receive the physical copy of their orders in order to book travel.

The OCONUS PCS time-line is honestly too lengthy for me to type here. However, as a spouse you are allowed to attend the PCS Levy brief where everything is explained. Most posts have a copy of the brief on their levy or reassignments website. You can also contact the ACS at your post and they will help with most of the information. You need about 90 days to successfully PCS OCONUS. Also, all the lodging is supposed to be booked with their travel card and all the tickets must be procured through travel by the member, so please do not get a jump start on those or you may spend thousand of dollars that you will not be reimbursed for.

Something isn't right. Normal circumstances- when a unit is preparing for or deployed, the personnel actions for school/unit assignment is frozen till after their return. Deployment can only be changed by DA, not branch, His Branch should have gotten notification of his deployment. Hell State Dept blocked on of my BN's from deploying to OP Urgent Fury cause they were prepping for MFO deployment in the Sinai.

They will either schedule him to redeploy early in order to complete the PCS process or push his report date back if the unit is under stop-loss orders.