I'm glad they're okay with it but then again what else would they post? npm has some major, major issues with it and it has barely moved in years. This Yarn looks like it solves quite a few issues with npm and it took another company to build it.
That's insane. It wouldn't surprise me if yarn becomes popular and its proxy to npm slowly turns off and boom, everyone would be migrated and npm would be left with little to no users. Yeah that's probably unlikely for the immediate future but Yarn is positioned perfectly to siphon off npm's users very painlessly.