They say it doesn't apply to them: "Fedora software in source code and binary
code form are publicly available and are not subject to the EAR in accordance
with §742.15(b)." Most of GitHub is probably also "publicly available" too
and exempt. But, Microsoft takes it further than they need to. They could for
example do something like this and not block people at all by just saying "If
you use GitHub you promise you're in one of those places...":
https://www.gnu.org/licenses/gpl-faq.en.html#ExportWarranties
The FSF has a good explanation there.
Besides; if you see a certain IP address it's hard to know that the person
actually is in that country versus, for example, someone located somewhere
else using TOR and their connection just happens to go through there.
Assuming that an IP address equates to the ending physical location is faulty
logic. In that case blocking these actually ends up blocking people that
shouldn't be by expanding U.S. policy to include people that should not be
affected.