I read during earlier attempts to pass the Copyright directive that it is not implementable in Poland because it would be unconstitutional. I understood that was why Poland was voting against it, but that was in the summer, and I’m not sure if the version that passed is different.

You need to realize that the EU "directives" are not actually the law (aka the thing that will get you prosecuted).

The directives are "transposed" into national law, country by country - and each country can (and does) add a local "flavor" to it. So if the Poles have watered down the anti-circumvention clause (it is very vague in the directive, giving a ton of maneuvering space to the national parliaments), the situation he is describing is very possible. On the opposite side of the spectrum is traditionally France, with its (fortunately incredibly ineffective) three strike system. Very different approaches to things even though both countries are implementing the same copyright directive.

The other type of texts coming from Brussels are "regulations" - those go into effect immediately, without having to be rewritten into national laws. GDPR is an example of such regulation.

You're absolutely correct. However,in the event that directives are not transposed (or not transposed correctly) courts can find that the directive is (vertically) directly effective.

I am aware, that's why I wrote "some implementation of", which needs to be checked. I am skeptical about the blanket statement made, it's usually more nuanced.