I'd recommend against this strategy, in general, why would some core functionality of a website depend on the ability to contact ad servers? Sounds like a way to pressure people into not using ad blockers, and the threat needs to be responded to (and can be responded to) by that ad block.
It's a really shitty game they are playing, because content providers can't win, but they can make the internet much worse.
Adblock doesn't just block ads, it blocks based on a blacklist that sometimes is a little overzealous. For example, I could block images.yahoo.com, but that would block all images from Yahoo. Maybe that's fine, since I never go to Yahoo. Then a blog post I'm reading has a picture that is hosted at images.yahoo.com, and suddenly Adblock is hampering my viewing of a site that I want to see. I disable Adblock, find out what was being blocked and why, and edit the filters to fix that (or completely whitelist the site, if the ads are non-existant or non-intrusive).
It's a really shitty game they are playing, because content providers can't win, but they can make the internet much worse.