Undoubtedly to prevent Starlink from making any observations about the current position of their phone.
Why not just avoid signing up for starlink service? I think you have to ask and be invited into the test.
Starlink essentially just provides additional cell tower sites to your network.
If you don't like your network using these for whatever reason, the best action would be to use another network.
This is sound short-term advice, as long as there are carriers that do not support Starlink. Voting with your feet / wallet only works as long as there are viable places for your feet and currency to go.