Imagine Debian banning Debian forks downloading from their repos…

If Microsoft are going to call VS Code “open source”, then the marketplace should not be selective on clients. If so, it’s not Open Source, it’s Sparkling Virtue Signalling!

I don't see why they'd need to make the marketplace fully open for their client to be open source. Fedora packages a Flatpak client that downloads proprietary software, but that doesn't make Fedora Sparkling Virtue Signalling.

Hell, Debian's repository now also include proprietary code (https://www.debian.org/vote/2022/vote_003) so binary BLOBs are perfectly capable of doing distro checks and refusing to run on forks.