The Anti-AntiAdblocker uBlock Origin filter to get rid of the annoying YouTube message. It turns off the JavaScript anti-adblock payload.

https://files.enderman.ch/scripts/yt-antiadblocker.txt

update, looks like the link is dead, but here are official instructions https://github.com/uBlockOrigin/uAssets/issues/19976

@yogthos Unfortunately, this doesn't seem to work on my end.
@win8linux doh, another option is to block the UI element for the popup, I ended up doing that earlier
@yogthos @win8linux Unfortunately I'm not getting a popup anymore (although I did get it for a few days), but the entire video player is now replaced by this message.