While you should do this to block your TVs telemetry and other undesirable behavior, realize that YouTube native TV app ads can’t be blocked at DNS level alone without also blocking the core functionality of YouTube, due to the way it serves the ads.
Don’t forget it also created a 5-10 year period of otherwise-tech-illiterate ditsy chicks with comm or marketing degrees rebranding themselves as “Social Media Marketing Expert”, because they knew what buttons to click in Facebook UI.