Mozilla tried to explain this change by, IIRC, claiming you had misunderstood, and that their behaviors ran afoul of the legal definition of “sell”. They did not clarify what they were doing, which could be counted as “sale.”

Ironically, after eroding almost all the trust in even much of their die-hard user base, they recently announced an AI initiative to “build the world’s most trusted software company”

(edit: fixed link)