Speaking from personal experience, it is necessary to update these references, because people implementing them have no choice but to follow the letter of the law. I have worked on govt projects where we had to downgrade to an insecure cipher suite to comply with outdated regulations.

Putting on my govt contractor hat, there may be a business opportunity here to set up VMs running Win95/Netscape Communicator for use by all the civil servants looking to comply with the law. Could charge a pretty penny too - it’ll all get budgeted as “Brexit compliance” costs.