So, is it legal? I'm happy to amend the article if this is the case, but my understanding (when I initially read that UK citizens were loosing some rights being moved to US) is that moving to Google LLC I will have less privacy rights.

According to their email, they think I'm a UK user:

"because the United Kingdom (UK) is leaving the European Union (EU), Google LLC will now be the service provider and the data controller responsible for your information and for complying with applicable privacy laws for UK consumer users"

But I'm not.

I can't say they are doing this intentionally, but it's surely a mistake and there is no way to reach them for a complain.