As long as you put back the same amount that you disposed, or made sure the level is full, it should be fine. You can never get a 100% change unless you do a transmission flush (which I think is not a good thing to do anyway).
Oh, I thought you DIY
If the workshop knows what it's doing, and made sure the fluid is full, then it should be OK. But might want to go back after a few days to double check.