This query hits the blob storage directly. Yes

When you say check the state of CDN, do you mean check if it is available? Or, do you mean check if it is stale? Because I think checking if the blob is stale or not may not be worthwhile and might be expensive

Assuming you mean the former, I am guessing if CDN endpoint is unavailable, azure will pull the blob from the blob service endpoint and cache it in CDN. I am guessing it is not for us to validate, right? Am I missing something?
Assuming you mean the former, I am guessing if CDN endpoint is unavailable, azure will pull the blob from the blob service endpoint and cache it in CDN. I am guessing it is not for us to validate, right? Am I missing something?