There is nothing stopping you creating a EuroSQL or something as a fork of Postgresql. The question is why.
MySQL was originally European and the acrimony that led to the fork to MariaDB didn't start until it was bought by Oracle. Until Postgresql is bought (if that is even possible) by a company with questionable practices I don't necessarily see a reason for it. And without enough reason (or enthusiasm) forks don't tend to live very long.