I’m not arguing with you on the matter. I think what Tesla is doing hurts the brand. The fact that they have the legal right to remove (or even add) features once they obtain possession of the car from a prior owner doesn’t mean It is right. Tesla has a disdain for all 3rd party non-Tesla dealers and wants to control all aspects of their cars. In this regard, they operate as if they own the cars at all times (even after a sale of the vehicle) and all you have is a license to use the car.
As to your question, removal of the LTE module would result in the non-functioning of features of the navigation (traffic indication, re-routing due to traffic, etc), non-function streaming of internet services such as Tunein, etc., not being able to access the car using the Tesla (or similar) app, and no longer receiving firmware updates (not necessarily a bad thing these says). In this regard, Tesla requires that all cars sold after a certain date (would have to check the website for the effective date, which I believe was in 2019) be connected to the Tesla mothership to receive updates which must be installed in order to maintain the warranty. And yes, Tesla knows what updates were sent to your car (based on the VIN) and what date each update was installed and whether the update was successful or failed. (I found that out the hard way when I refused to update my car for months because I did not like version 9 of the software and then one day Tesla forced the update onto my car and when I confronted Tesla about it they pulled up on a computer screen the log showing me the date each update was sent to my car and the date I then installed the update).