It probably doesn't even make a blip on their radar. I wonder if even browser-based adblockers are really an issue for them, and they most likely have couple orders of magnitude more users.

It is technically possible to block the IP ranges of reading/caching web apps, as well as refusing to show content to readers blocking ads, but few providers bother. Neither usage scenario is practiced widely enough to significantly impact ad income, except on sites that serve a very tech-proficient userbase.