Well, all the distros being discussed are open source - it’s kind of a requirement when making a linux distro because the licences require it and you wouldn’t be able to make it closed source. (Unless there’s a huge shift in the law)

And being open source doesn’t necessarily prevent it falling under sanctions legislation. I have seen a linux distro being legally required to “take reasonable steps” to geo-block Russian access to its repos, and I’ve personally read disclaimers when installing linux that “This software is not allowed to be used in Russia”. (That distro is ‘owned’ by an organisation that was controlled by a single person, so it’s probably not comparable to Debian) We’re all technical people so we can all probably think of half a dozen ways around that, but it was still ordered by the US Government (even before the current government)

And you may be right in that it would be excempt. Debian isn’t owned by anyone, but its trademark is(Software in the Public Interest), and it feels possible that those who help distribute foss (by mirroring repos for example) may be restricted if they fall under US jurisdiction. I don’t know for certain - and unless someone here is a qualified lawyer specialising in software licences as well as how software rooted in the US relates to sanctions - we’re all probably guessing.

Three months ago any of this would have felt ridiculous - who would want to stop free software? But now? In this era of the ridiculous? I certainly feel unsure about predicting anything.