I don’t believe that’s correct. Tesla has to actually own the car before they can remove free supercharging. So if Tesla owned it or if it was bought from Tesla, perhaps in an auction, then you can expect to lose the supercharging. If Tesla never owns the car they cannot remove the lifetime free supercharging no matter how many independent dealerships it goes through.
You shouldn’t be afraid to contact Tesla about change of ownership. If they owned the car, they know so you won’t be telling them anything new. If they didn‘t, own it they cannot remove the lifetime supercharging.
Not only is that not true, but owners here have have copied communication direct from Tesla that states any third party dealer possession will revoke the FUSC. This should be absolutely illegal but until Tesla is challenged in the courts on this, they'll continue to strip away FUSC whenever a Tesla that has it has been sold by a third party dealer or goes through any third party auction even if it's private to private with the auction being in the middle.