It's stupid they would make foreign companies help them implement their own idiotic law. What would be the consequences of non-compliance considering they might ban this place by default anyhow?
As of right now, these are just rumors which I think are being dropped by people/companies who have invested large chunks of change into the whole age verification sector.
1. That google has agreed to delist non-compliant sites from its search. Now, I do think that this will happen for Google.co.uk since Germany has already set a precedent for any site that doesn't follow German age verification laws. If you go look for FreeOnes or Pornhub on google.de you're not finding it. BUT if you are on a german IP and go to google.com, you'll still find all the porn sites as normal. The german govt can only really dictate what happens on the .de TLDs (including taking them away from people).
However, there have been whispers that the UK reached a deal with google to delist any non compliant site across all the country domains including .com. If so, this is huge, huge overreach. This is why I think it's a rumor to scare the majority of little sites into compliance.
2. It's also rumored that the UK has reached agreements with Visa and Mastercard to drop processing for any non-compliant site regardless of where they are in the world. This one is just down right chilling.
Payment processing is the life blood of any site. What most people don't realize unless you do something within the porn industry that requires credit card processing is how much control the banks, Visa and Mastercard has. There are words we can't have on the site down to not being able to have any video where there's red wax, red lipstick, strawberry syrup, etc on someone because it "could" be blood. Everyone puts up with it because if you lose your processor, you can just pack up and go home.
I don't think the UK can really dictate what a company in another country, who doesn't host in the UK and doesn't have a .co.uk domain can do but starting this rumor is a really good way to scare anyone who can't afford a good lawyer into compliance.
Really, all we can do is wait and see what happens. I'm not really convinced the law is going into effect this year since they still don't have a lot of shit in order yet. They only now released the guidelines so this means all the age verification sites who didn't guess right has to go fix their code to make it compliant and anyone who's a developer or works in website development knows that this may mean starting from scratch.
So we'll see!