"We" is the NIP repo, which provides guidance on how to use nostr. It's not a spec, but a description of what is happening in the Nostr ecosystem.

Lots of clients have proposed HTML encoding in kind 1. Multiple issues are asking for markdown in kind 1. It's just about time for a new client to come and start putting other syntaxes in kind 1. People can add and modify tags for their needs, breaking the past, like what the folks in the PR were proposing.

If we insist on getting every new client, we are just creating more problems for ourselves.

I am fine with it because I will integrate everything that shows up, but many other clients won't be able to manage it. So, I think it is better if we make it optional and more specific to Twitter like posts.