No, that's what they claim, but it's bullshit. Even the most "broad and evolving" definition of "sale of data" still entails Mozilla having the data at all in the first place, and that's the bright red line they shouldn't be crossing!

If you want to get into the blog, here's the relevant part:

In order to make Firefox commercially viable, there are a number of places where we collect and share some data with our partners, including our optional ads on New Tab and providing sponsored suggestions in the search bar.

See that? That, right there: that's the entirely fucking unacceptable part!