General rule of thumb: Every time an organization updates their terms of service and/or privacy policy, it is never because they have your best interests at heart.
Specific thoughts on this latest Mozilla action (https://blog.mozilla.org/en/products/firefox/firefox-news/firefox-terms-of-use/)
Setting aside the "worldwide license" bullshit, the privacy policy appears to have broadened both the classes of data Mozilla aims to collect, and the situations in which they collect them.
These are not the actions of an org that cares about your privacy.
A new slate of Mozilla top executives launched these changes, and introduced Mozilla's first ever Terms of Service. It never had them before.