[shawnz]

If the TV manufacturer wanted to implement this mechanism, they wouldn't need DoH to do it. They could just put the ads right on online.movies.example.com and use TLS there. Any kind of ad-blocking mechanism based on DNS is trivially bypassable.

Suggesting that we should weaken encryption/privacy because some people plan to use it in ways that we don't like is just not a viable option. It's exactly the argument that governments are trying to use to mandate backdoors in our chat services. With encryption, it's all or nothing.