I own a BMW i3 and the Tesla Model 3. Both have cellular connections and are constantly pinging their motherships. At least on the Tesla I have the option of opting out. No such ability is available on the BMW.
You most certainly can prevent it from paging home to BMW. Either thru the settings menu or hacking it via ODB2 port and coding it off with software like E-Sys.
I mean, it's the same software the a BMW dealership uses when they code your car. I was easily able to learn how to code my own BMW using it within a day. It's not hard.