It raises the question: what is a distro since many distros are customizations of other distros. What makes Ubuntu a distro and not just a customization of Debian?
The video above is in inline with my opinion. If you ship an ISO (so users can install your distro directly without installing another distro first) and have control over the packages then you are a distro. Apparently, Omarchy has its own ISO and it's own mirror of the arch package repo so it is a distro by that definition.