Whilst the messaging here is chilling, I don’t think E2E will be banned in the UK. Not least because journalists and MPs use it everyday in signal and WhatsApp.
I've said it in previous threads on the topic but something like this has probably come up once or twice a year for the past 20 years. Encryption, porn, age restrictions on the internet...
We shouldn't become dismissive of it that way but I'm sure this will conveniently fall off the radar when it's served its purpose. But it should be noted that our PM Boris Johnson referrs to something like this as a dead cat: throw a dead cat on the table and everyone's looking at the dead cat, not the other thing that's going on.
See BoJo's Christmas Parties and weekly "work meetings" for details.