My guess is that this is a propaganda effort meant to counter that EU countries is putting pressure on social media to moderate hate speech and importantly disinformation.

Having an official US government site means both that it will have higher apparent legitimacy (compared to a random X post) for people who want to believe. It’ll likely also mean that there is no European corporate presence to pressure so the only option would be to escalate to blocking the entire site, which I don’t see happening tbh.