I want to understand the point of the CC's added to the pull request description, are they necessary for the Git mailing list submission to correctly send to all CC's?

If not, should it be replaced by a nicer message in order to send a better patch diff description when submitting to the Git mailing list? Or rather, can we make it so that /submit accepts a message to send instead (maybe it already supports that?)

For context, see this message from Junio Hamano: git/git#2138 (comment)