From the new terms:
When you upload or input information through Firefox, you hereby grant us a nonexclusive, royalty-free, worldwide license to use that information to help you navigate, experience, and interact with online content as you indicate with your use of Firefox.
It doesn’t allow for any use of your data. It allows for use of your data to do the things you ask it to do. That permission is implied by you asking it to do something, but it isn’t explicitly stated.
The AI clause is conditional. It only applies if you use the AI features.