Sounds good to me. (DuckDuckGo teaming up with Firefox, I mean.)
This was the very first time any meta search engine (search engine that combines results from multiple search engines) was added to any of the most popular browsers.
They've also added it to Firefox Focus (at least at the time when it was released on Android).
So, it's fair to say that they have some sort of collaboration between them. Wouldn't count on it getting more serious than that, but I would still love to see it happen.