One of the core functions of Court of Justice of the European Union (CEJU) is to perform judicial review, which means they can strike down laws. So it would not be legal to pass legislation attempting to make legal what they struck down.
In this case my understanding is that they determined vpn-s as a tool to fall outside the scope of the law and so they struck down an attempt to enforce the law
If the law got changed so that vpn-s are now within the scope of the new law then you'd expect them to not apply the same reasoning anymore in examining a similar case
Judicial review would come into play if the challenge was about the updated law being inconsistent with some more important law such as the treaties or charter