When you purchase a Tesla, you are given no promise of free loaner cars when you are in for service. What you get will depend on the current policy at the moment, and the availability of cars to the service center.
They cannot give you a car they do not have available. They are not contractually obligated to give you a free loaner, and they are not contractually obligated to even give you Uber/Lyft credits.
When they provide you with free transportation, it is provided as good will and they can provide as they see fit. You have no right to demand free transportation when your car is in for service.
If they are out of loaner cars, they cannot make them magically appear because you conjure up some story on how it is essential that you get a Tesla loaner (or even enterprise ICE)
Elon has stated his desires and expectations, but his desires are not contractual obligations.