Oh for gosh sakes, that’s the dumbest thing I’ve heard today. But then, it’s morning. There’s time. lol

So here’s what I’d suggest. If your other blog is on Wordpress, go to the list of blog posts and hit Quick Edit. Change the publication date to the current date — import to Medium — then you can change back to the original date on your WP blog. If the other blog isn’t WP, I got nothing! :)