There has been no further information beyond Dorsey's tweets, although it's notable that the new hires will have the option of being paid in bitcoin, something Dorsey has long championed as the world's single native currency of the future. Square's cash app already supports bitcoin purchases and sales, so it will be interesting to see what the team will be working on.
Dorsey added that building upon the current crypto ecosystem is "the most impactful thing" Square can do for the community right now, adding that "Square has taken a lot from the open source community to get us here. We haven't given enough back. This is a small way to give back, and one that's aligned with our broader interests: a more accessible global financial system for the internet."