For context on why any account flagging is ever necessary, unfortunately, every company in the world is required to comply with US sanctions if they do any business at all in the United States, e.g. serving US-based customers. This includes even interacting with US banking infrastructure. So being headquartered somewhere else doesn't help; you have to comply. And US sanctions as written do not allow us to provide commercial services or services which could be used commercially to sanctioned countries.
We are taking the broadest possible interpretation of US sanctions law to allow as much access to GitHub as possible and we are, as far as I know, the only major vendor to offer public repo access in US-sanctioned countries like Iran, Syria, and Cuba. I'm proud that we are taking this strong position to ensure developers everywhere can participate in open source.
I wish we could also offer access to private repos and still comply with government requirements. We have been advocating and will continue to advocate for broader developer access with the various government agencies involved.