Pihole won't solve it, unfortunately. The only way to block it is to have a Chrome/FF on the media device plus adblocker. But that's very complicated topic and when I checked there were no suitable distributions and ways to get it. I ended up getting a proper PC and using it as a media server instead of pi-like devices.
Does pi-hole remove Youtube ads? pi-hole can only block whole ad domains. I would be surprised if Youtube deliberately served ad videos from a different domain than regular videos.