Here's the plagiarizer's new Substack profile: https://substack.com/@michaeldehaan - the profile was created 2024-04-26. That's not the actual author, it's someone stealing Michael's content under their own name.
For now, please be suspicious of Substack-hosted content - here or elsewhere - from anyone without obvious reputation. Obviously stealing old Substack hostnames and posting otherwise-identical content on the orignal URLs is now a thing. Their URLs are not as stable/consistent as we all (reasonably!) assume.
Substack, if you allow old hostnames to be re-used, how about removing the ability to use the same URL slug? Or at least removing the ability to back-date posts? It's probably worth looking for old URLs (ie, hostname+page slug) that have been re-published by different Substack accounts, too - obviously this flaw is being exploited.
Plagiarizer, you're obviously active on HN. Can you share more about why you're doing this? Boredom? Substack monetization grift?