Can ANY soft brick be repaired?

[RobMerrell]

I accidentally soft bricked my Galaxy S6 by not unlocking the bootloader before flashing a ROM. I managed to reset the phone using Smart Switch, but I proceeded to re-root the phone. However, I was not aware that you had to keep OEM unlocked while rooted, and I did not enable USB debugging. When attempting to reboot, I was met with the message "Custom binary blocked by FRP lock." I am not able to re-flash the stock firmware, as I had not enabled USB debugging, but Samsung Smart Switch fails each time I attempt to use it. I am bringing the phone to Best Buy tomorrow to attempt to have them professionally re-install the original (and official) firmware, but they have stated that the process is hit-or-miss. Should I count on the phone being repaired or dead?