Did you ever get your answer?

I'm in a similar situation. I had a 6l80e rebuilt from a 2014 Silverado 1500 4x4. I have the original tune file from the TCM. I'm being told the rebuilt transmission has a new TCM that needs reprogrammed before it will work. Can I flash the TCM with the file i saved from the old transmission and be good to go? or do I need to pay someone to come flash the TCM as the transmission shop is suggesting?