Thanks for all the info. I’m planning to get it into a transmission shop today. I feel pretty silly to have let a the employee talk me into pulling out the fluid. They did not charge me for doing it. The car has ~125,000 miles on it. The good news, I guess, is that the receipt does state that they removed 3 quarts. I also have receipts for two of the return visits that show how much fluid was added back in on those visits.
BTW, this transmission has a procedure that must be followed to check the transmission fluid. It involved putting on the parking brake, running through and pausing in each gear, then ending in neutral. Properly done, the level is checked while in neutral. They checked it in park.