I'd love to see them push for Mastadon. They can serve as an entry point for a lot of people because for the layperson, the fediverse is an odd place that's kind of hard to understand.

If they can just be the, "hey join Firefox.social and you're in the fediverse. Here's our Fedifox app for your phone, bing bang boom." I think it could go a long way to growing the total userbase.