This is absolutely correct. My service advisor stated BMW has clearly laid out procedures for different warranty claim problems, that must be followed in order to receive reimbursement.For BMW warranty service the dealers must follow a prescribed BMW script to address each type of issue. Depending on how that goes BMW may or may not instruct them to update or modify software. As mentioned sometimes new software can fix one issue and break another so they try not to update the major software set unless all else has failed or it's required for a known issue.
You can see it on the notes at the bottom of the invoice that was shared above. They. Are notating the steps they took according to that script. When I had my G12 in for the flaps they actually had to keep the car multiple days because they'd try a step without success, enter the notes into a BMW system and have to wait for someone at BMW to review them and give them direction for next steps.
He said if you come in out of warranty, they will often cut to the chase in order to try and save the customer some labor on the fix.