Been following Mario and Armin (much longer), and this is a good move for all parties involved. Would have been bad if Pi went the same direction as RoboVM (mentioned in the post). Earendil, as a company, is not clear for me yet but one of the projects Armin is working on that's part of this is Absurd[0], which is also an interesting project. Absurd, like Pi, is minimal and let's you have full control.
[0] - https://github.com/earendil-works/absurd