RFC 9051 says that it was "developed for" RFC 822 and that one should now refer to RFC 5322 instead. And RFC 5322 does discuss threading, which is the what the comment you're replying to was talking about, so that concept does appear (by reference) in the IMAP standards.
Are there other parts of the community that implement IMAP using the same "mental model of email" that Gmail is using? Or are you saying that anyone using IMAP with anything but Gmail is an old nerd and a tiny minority?
RFC 9051 says that it was "developed for" RFC 822 and that one should now refer to RFC 5322 instead. And RFC 5322 does discuss threading, which is the what the comment you're replying to was talking about, so that concept does appear (by reference) in the IMAP standards.
Are there other parts of the community that implement IMAP using the same "mental model of email" that Gmail is using? Or are you saying that anyone using IMAP with anything but Gmail is an old nerd and a tiny minority?