I wonder if it can be detected by the streaming apps. Some of them are really anal about ensuring you can’t record or whatever, and don’t work if it doesn’t get all the HDMI security stuff just right. I’ve had issues with bad cables and my portable projector(Anker) has to side load an alt version of Netflix because they couldn’t/wouldn’t get the device to pass Netflix “certification”.
I’m guessing this means new partnerships and money changing hands, or nobody on a Roku can watch Netflix anymore, or they put these ads at a higher level that bypasses whatever security/DRM Netflix uses. Probably the last one, but if Netflix thinks they will lost money to this they’ll probably just pull their certification anyway.