Quite recently I was asked on a meta site to post my original question from there onto the main meta instead, as it would be of StackExchange-wide scope. I then followed the moderator's advice, and then later another moderator closed the original with the notice "closed as off-topic".
That felt a little weird psychologically. Would it be possible to offer an option/notice "closed due to duplicate on main/other meta/site" or "closed due to requested migration" or some such? Even if "direct" migration is the desired mechanism (and preferred over reposting with deletion of the original), it might sound more positive/motivating/encouraging to beginners. (And, additional mechanisms such as what I'm proposing can never hurt, even if they're technically superfluous - in this case, because the user should (very much arguably) not have posted on the site meta in the first place.)
(I know there are similar questions here, but I think this specific issue merits some attention. Do correct me if I'm wrong.)