Based on the parent, all the collected data preserves privacy:
> Firefox also shows its own search suggestions based on information stored on your local device
That data stays on your computer ...
> Mozilla processes [...] how many searches you perform, how many sponsored suggestions you see and whether you interact with them.
That description contains no user content: number of searches, number of ads, whether you interact says nothing about you - it doesn't say what you click on or see, just that you clicked.
> position, size, views and clicks on New Tab content or ads
Again, there is no content mentioned, just number of clicks and not what you click on.
> [Definitions]
This section defines terms; it doesn't say they are doing anything.
> Firefox also shows its own search suggestions based on information stored on your local device
That data stays on your computer ...
> Mozilla processes [...] how many searches you perform, how many sponsored suggestions you see and whether you interact with them.
That description contains no user content: number of searches, number of ads, whether you interact says nothing about you - it doesn't say what you click on or see, just that you clicked.
> position, size, views and clicks on New Tab content or ads
Again, there is no content mentioned, just number of clicks and not what you click on.
> [Definitions]
This section defines terms; it doesn't say they are doing anything.