Sorry for the confusion.  This problem is only going to affect those
whose IMAP servers don't support the MOVE extension, which is probably
why it was overlooked.

I tested with courier, dovecot, RFC sample sessions and gmail IMAP
transcripts, FWIW.

sean
[0]
tagged in COPY response
https://tools.ietf.org/html/rfc2359#section-4.3
untagged in MOVE response
https://tools.ietf.org/html/rfc6851#section-4.3