It usually comes up during a repair job if the owner thinks he can retain calibrated settings even after the repair. So he says something about it to the repairman and gets "caught" so to speak.
General rule of thumb about professional calibration is don't ask , don't tell. Give a manufacturer an "easy out" from servicing your TV ... and they will take it. You then spend the next 4 to 6 months arguing with them on the phone and email ...
At the end of that time ... they usually relent and reinstate the warranty ... which is now 6 months less.
So the lesson is to keep the mouth shut unless you particularly like confrontation and agrivation.
Calibrators and manufacturers walk a fine line and do a careful dance. Reviewers of products routinely calibrate the TV they are reviewing. Manufacturers know this full well. Set gets proclaimed "TV of the Year" and the manufacturer takes all the accolades. Now you try to get it calibrated the same way and mention it to the TV maker ... whoops ... canceled warranty. If it costs them money ... they will try to get out of it.