You can see what API calls do not work on the listed page. Most of those should not require any privacy breaking features so it should absolutely be possible to implement them legally. They just don't like to do so.

This is just speculation on my part, but if facebook implemented these API calls in a privacy-respecting way for the EU market, then it would be very easy for the US government to suggest that the already-existing privacy-respecting version should be used in their jurisdiction too. Maybe that's what facebook wants to avoid?