Github, Facebook, Twitter, Youtube, Sourceforge, HN, Slashdot... These free services are not public. You might treat them as such, but you are foolish believing they are.
If you cannot see the difference, I suggest to read the excellent Wikipedia article. [1]
We should be putting our collection of code in something else with a mission around those ideals.
I put it in quotation marks because it is my laymen's understanding of what the sanctions are intended to cover. I could be wrong and the actual boundaries could be subject to debate and disagreement.
I think they've realized that the argument that they are a commercial publisher is quite strong. Thus they are not eager to challenge it and wind up heavily fined for sactions-busting. Especially since Microsoft is a significant supplier to US government entities.
Meanwhile for decades I remember many software EULAs saying things vaguely equivalent to "don't use this software in Cuba", etc. That is what I would compare this to.