It’s not unconstitutional for a company to think that they need (or want) to do something in response to a sanction.
GitHub is not in the business of being legally innovative.
GitHub is not in the business of being legally innovative.
Yes. This isn't what happened. The code isn't sanctioned, the organization is. And these people were affiliated with the organization.
Nobody can say what GitHub would do. But they’d unlikely be under legal jeopardy from hosting it. (They may not want to bother with monitoring whether you continue to develop it or not, however.)
As I understand it, you are free to develop it. GitHub can't stop you from doing that. I'm not sure of your point here.
If you continue developing it academically, that’s fine. If you’re developing it to deploy it, that could be problematic. Most people don’t want to deal with customers where they have to monitor that distinction. (Those folks can always just host the code themselves.)