This is kinda pretty ridiculous.

Isn't GitHub's entire visibility and pervasiveness is entirely due to the OSS?

So, now they're basically saying to OSS, "so long, and thanks for all the fish"?

Github as a platform itself though, isn't open source.

it seems like anyone continuing to use github is ok with providing free labor to Microsoft. Not that that wasn't the case already, but now it seems especially blatant. "open source" is just corporate welfare at this point.