No, it absolutely is not. That's a myth.
Individual cars never ever learn. (troubleshoot'd be a nightmare for one thing- nor does the car have remotely the power, or tech, to label and train NNs onboard)
Changes in behavior only happen with firmware updates from Tesla- all AI learning/training happens back at HQ.
On the current wide-release versions of firmware, when you disengage only a very very tiny report goes to Tesla- No pictures, no video, just location is coordinates, how did you disengage (brake, wheel, stalk), speed, heading and time. That's it. Under 1kb of data in the report.
Useful to tell them "Hey AP has trouble with this one location" when a lot of reports in the same spot come in, but that's it.