We weren't born yesterday, and companies pull this shit all the time. This sentence is meaningless. You could use this sentence to justify literally any behaviour.
One _easy_ way to read this change:
> "... to help you interact with online content"
Selling your data to have more relevant ads could easily be justified as helping you interact with online content
> as you indicate with your use of Firefox.
Using firefox indicates that you want us to do this.
Or,
we made it an opt-out that is quietly rolled out in an update.