But Microsoft generally supports policies for enforced disabling features like the one referenced in the post. Similarly, data exfiltration from managed to non-managed devices is an entire cottage industry. And generally that's why govt employees are expected to use separate, locked down devices where their compliance-obsessed (hopefully, but not always in practice) admin has total root.
And I don't believe you're implying this, but certainly I don't think it makes sense for companies to _not_ build internet/cloud-connected experiences and features just because there's a possibility that govt officials won't follow their own security policies and best practices.
From the perspective of Classified Data this SHOULD not be a problem, but I highlight the "SHOULD" because sometimes these barriers get crossed unintentionally. Mission briefings, etc. may accidentally leak info, and those are almost all PowerPoint.
For the ITAR data though, that's absolutely not only on isolated networks.