The Texas Department of Criminal Justice will not tell you the destination in advance, and that is standard policy across virtually every correctional system for transfers of any kind.
Transfer routes, destinations, and timing are kept confidential for security reasons. It protects the inmates being moved, the transport staff, and the integrity of the process. That information does not get shared with family members ahead of time regardless of the circumstances or how the question is asked.
SAFPF, the Substance Abuse Felony Punishment Facility program, operates at several locations across Texas. Which one your brother gets assigned to depends on bed availability, his classification, and where the TDCJ places him based on their internal process. You will not know which facility until he has arrived and is able to contact you.
The communication blackout during a transfer typically lasts a few days to a couple of weeks. He will be in transit, then going through intake and orientation at the new facility before phone access is restored. When he is settled and able to call, that is when you will find out where he landed.
Once you have his new location, update his contact information on any accounts you use to send him mail or add phone funds. In the meantime, a letter sent through InmateAid to his current Wichita Falls address is worth sending now so something familiar is waiting for him when he arrives and gets his mail forwarded.