Considering that nothing is set in stone at twitter (X now?), would be cool if Discourse forked and kept a copy of the emojis if this hasn’t been done already.
Fork by former Twitter staff that I saw being used on another project: Release v14.1.0 · jdecked/twemoji · GitHub
They’re already bundled in Discourse here: https://github.com/discourse/discourse/tree/f6d97eef0829e3392b98359b48ddd253f7f8fc2a/public/images/emoji/twitter
These are already open source, so twitter can’t un-open source them or do much damage retroactively… I guess in the event that they stop making new ones we’d have to look to forks like the one @nolo mentioned.