The definition of the word "sell" has a different meaning in a post-AI world and in specific California have a new bill adding some other contexts to it, so despite not actually doing anything differently (go and look at the Firefox source tree if you don't believe me) they have to change their wording.

ETA: Setting Google as their default search engine in exchange for funding from Google has been cited as an example of "selling user data to Google", if you'd like a concrete example of what I'm talking about.