You can when it comes to copyright. That’s EU-law and anything else would be such a horrible idea that no country would ever set up a law saying otherwise.
If you could simply revoke copyright licenses you would completely kill any practicality of selling your copyrighted works and it would fully undermine any purpose it served in the first place.
They absolutely can, you gave them an explicit (under most circumstances irrevocable) permission to do so. That’s how contracts work.
Unlike in US, and I cannot speak for all of EU, but at least in Finland a contract cannot take away your legal rights.
You can when it comes to copyright. That’s EU-law and anything else would be such a horrible idea that no country would ever set up a law saying otherwise.
If you could simply revoke copyright licenses you would completely kill any practicality of selling your copyrighted works and it would fully undermine any purpose it served in the first place.