As part of the aforementioned EU law, there's a list of countries to which it applies. The two you've mentioned aren't on it. You can look it up in the Amsterdam treaty if you'd like :)

edit: here's the law for your convenience: https://eur-lex.europa.eu/legal-content/SK/TXT/?uri=CELEX:11...

So an EU law that doesn’t apply to the whole EU, that bodes well for a confederate project.

Isn't that what the article is arguing for though? A multi-speed Europe?

Count of disingenuous to argue for a multi-speed Europe starting from now on when we have been a multi-speed Europe already. I'd be perfectly fine with that, too, but getting rid of the unanimity thingie is just asking for trouble.