... Well, good question! I believe the answer to that is "no".
You can read the base specification here:
https://cr.yp.to/proto/maildir.html
The idea is when you are delivering a new message into a Maildir, you
first write it to the "tmp" directory, then rename it to the "new"
directory. Then something (presumably your IMAP server or MUA) will
notice the new file in "new" and then move that file into "cur".
Now if we refile a message, do we put those messages in "new"? Maybe?
But then they won't be visible to other programs until the true "manager"
of that mailbox notices it. If we scan a Maildir folder, should we be
in charge of moving stuff from new into cur? Maybe? Maybe not? You
tell me!