It would be pretty trivial for them to just block playback completely for any agent that’s blocking their ad scripts. Or make their ad videos indistinguishable from the actually video you want.
The question isn’t CAN they enforce this, it’s WILL they enforce this? Thus far we’ve been succeeding at this cat-and-mouse game simply because the cat is too fat and lazy to chase us. But this cat is looking more hungry and motivated every day…we’ll see.