The immediate difference is that everyone is affected by the Great Firewall, not just "designated persons". How it turns out in practical use surely remains to be seen.
The title is misleading - this requires all ISPs in the UK to ban anyone from visiting rt.com, not just "designated persons". And indeed it works - I'm in the UK and trying to visit that website times out on mobile or cable broadband.
EE has just removed the DNS entry from their server. 1.1.1.1 still works.