Last time I checked modestly reliable geoblocking existed, and completely unreliable vpn blocking.
A friend told me that when he comes across a site for which Nordvpn is blocked, he just changes IP. Latest the third one always works, even on YouTube (he is all about privacy).
However, to address your specific chosen example, one could argue a difference from murder, if they say “your site must block these traffic sources or you’re in trouble”: one could argue (it’s not at all cut and dried) that it’s like saying that venues are liable for the murders committed at them, rather than the murderer.
Something that's extraordinarily low effort will become exceedingly high effort, and this will achieve their goals.
It says that a site that distributes harmful content for minor, like, let's say, xvideos, will have to block vpn users from wiscosin.
Yes. that will mean, that if xvideos will wish to be compliant with Wiscosin laws, they would have to figure out a way to block all vpn users.
Bad. Really bad.
But no, it's not like Wiscosin citizens will be prevented to work remotely using a VPN to connect to their corporate network.
https://aws.amazon.com/about-aws/whats-new/2020/03/aws-waf-a...
Even if you somehow manage to enumerate the Nordvpn IPs - a thing of which Nordvpn probably thought in their threat model - then you still have thousands of other providers.