I wonder if the only part that changed is now the have a user-facing way to deactivate: https://selfsolve.apple.com/deregister-imessage/ https://selfsolve.apple

I wonder if the only part that changed is now the have a user-facing way to deactivate: https://selfsolve.apple.com/deregister-imessage/ https://selfsolve.apple.com/deregister-imessage/ iMessage was launched in 2011 and archive.org shows that page first showing up in late 2014. I remember hearing very few options for removing your old phone early on.