The Register is only showing an example of #3, but leaves #1 and #2 unaddressed:
1. Your Identity (who everyone is)
2. Your Conversations (with whom, when)
3. Your Content (what was said)
Does the UK government have the ability to identify #1 and #2 for E2EE connections, and they desire #3 (content)?
Is the UK government only able to identify #2, and they desire #1 (identities) and #3 (content)? If so, which is more important to them: Identity, or Content?
I suspect they are much more desperate for Identity and Connections, than they necessarily are for Content, and that their attempt to overreach and backdoor all encryption could be shutdown by offering them #1 and #2 but not #3.
This is obviously unpalatable to consider to "perfect anonymity is the only way" adherents, but it's probably time to consider discussing it, when the alternative is a government backdooring or banning all encryption. It's too bad The Register didn't take that chance, but we could at any time.