It's kinda sad.
The European Commission even has their own Mastodon instance (https://ec.social-network.europa.eu/), but it seems they can't get any of the Commission employees or Parliament MPs to use it. It only has 10 accounts and from what I can see, only one "real" active user, Veronica Gaffey the Director-General, for Digital Services (DIGIT), who isn't even posting on her real account but under the title @EC_DIGIT_director_general
As far as I know none of the EU member countries have their own Mastodon servers and most politicians at least here in Sweden seem to be using either X or (the technically minded "progressives") Bluesky, while they complain about American Big Tech.
As always with politicians, actions don't correspond to rhetoric.
Regarding this "W" social media launch though - There's a post on the CEO's LinkedIn about a "pre-launch" in Davos, and that links to an German article saying the same thing - but there's no link to this launched site anywhere. ¯\(ツ)/¯