Question. Wouldn't the catch-all solution for YT is to pair the AJAX calls for the video with a "view video key", and that key to be found out after running a deeply obviouscated javascript served with the html of the "view video" page?
They could even bundle some of the key-building-js with the ad being served.
At some point in order to "block the ad" , the ad blocker would have to run or analyze tons of JS code , making the ordeal to difficult to compute.