More likely you have to connect to EU servers from the US to view EU users. But this is not really any more complex than adding another sharding split. Since model weights and embeddings are widely considered to not be user data either (they are derivative works) I don't think the EU's requirements have any real impact to privacy or FB's ability to operate.
All this regulation will only entrench the big players who can afford expensive software engineers to run globally distributed systems that respect privacy regulations. You can't just spin up some servers in us-east-1 and focus on building your app now. Your data is still getting vacuumed up, just on the EU continent instead of in a US datacenter. But NSA/Five Eyes has everywhere wiretapped anyways so your data is equally as unsafe as it would be in a US datacenter.
