If they are solely doing it for legal reasons, I would expect some form of malicious compliance - like an accompanying blog post explaining how it'll be marked as "Firefox is legally required to tell you the EU considers this page safe. We disagree. [Learn More]" and that the mark will only be shown to EU users.

Complying to the exact letter of a stupid law to avoid getting sued is understandable. Voluntarily complying to the broadest interpretation without any pushback is not.