OK, I can believe this has non-engineering issues. Still cannot "edit as new" for when you want to edit what you posted in the exact some editor state as when you posted it. What you edit and what gets posted can differ radically. This is well-trodden territory in the email world. Accordingly, Fastmail service has "Edit as New" and Apple's iOS Email App has "Send Again" for email.

I'm pretty confident Twitter could manage "edit as new" for Tweets, and it would be useful with or without tweet editing.