Adding @Saili Raje , she has been investigating conditional access policies and how they affect Stream. Saili - can you add more details on these questions?
Freddy - You are correct that Stream doesn't show up as a cloud app in AAD conditional access settings. Saili was looking into this and trying to track down what it means and/or how we can add Stream there.
We don't support external anonymous access in Stream yet, so I don't know if when we do that project there will be any other AAD CA issues.