Some but not all publications will do a dup check. I was an editor for 5 pubs on here last year. I did it with every submission and a lot of the other editors did as well. That's when you'll get caught.

Other pubs aren't as diligent which is shameful because it's part of the "job". But if they don't catch you then you run the risk of Medium AI catching you or another reader. It just isn't worth the risk.

I heard one time many years ago that you should always live your life above reproach. Aim high and you'll never go wrong.