It's also way less effective than they mentioned because they didn't get hacked either way. So there was 0% difference in effectiveness between port 24 and 22 since the ssh was properly configured.

Security by obscurity only matters if you aren't secure in the first place. It can be a good extra layer of protection, but the worst examples of security mishaps I've seen are because people find the security unnecessarily burdensome and so they bypass it entirely. So in that way obscurity in that case has a real cost.