Instapaper is sort of the only site where it's an actual problem. I get the feeling that the rest are just running on some common platform, which have the feature of being able to block the EU after some US corporate lawyer overreacted.
Given how US techies here on HN seems to constantly overreact and loudly proclaims how the GDPR means they need to hire 20 new employees and how they all will be suited into bankruptcy anyway...
If they are now stuck in a needlessly rigid legal regime, it's hard NOT to say they brought it on themselves.