Looking at the article talking about this proposal, it appears that the requirement is actually that it's as easy to cancel as it is to sign up, not that it is "one click." A confirmation box is pretty standard practice in UX for destructive actions and it doesn't sound like that is prevented.

What the proposal DOES do is prevent dark patterns, like having to click through five screens of offers before cancelling. Overall this is a very poorly written article. But it's gizmodo so I'm not sure what else people are expecting!

https://gizmodo.com/bluesky-engineer-q-a-twitter-alterative-...)