Yeah, it's legal to purchase and own a Cybertruck in Europe.

You just can't legally drive it on public roads, because it hasn't passed the safety tests.

They haven't even attempted, because it is evident that it will fail. So, they have not introduced the vehicle for sale in Europe

If you see one, it's probably a gimmick showcase thing. They did tour a demo model around for tv stations earlier this year, but I'm not sure what the purpose was. It was basically mocked everywhere it went.

It's possible and perfectly legal to import it yourself and then... put it in a garage or drive around your mansion all day long if you want.