In truth, the answer to your last question is: There isn't much difference.
We do allow all sorts of bastardised installations on here.., assuming that they come from a pure origin. but allowingBut expanding that to change site policy would changemean swapping our curtshort whitelist into a saggy blacklist. It would mean peopleWe would also need to checkmaintain the what-we-support list and it would take a lot of time to inspect how a distributiondistro is builtconstructed (to make sure it is just a simple respin) and... And we'd need to revisit this over time everydo that every release of every distro. It'sThat is not fun work that doesn't help peopleand worst, it doesn't help people and that's work I try to avoid generating.
It is simply more simple to stick with the official releases, with the official support periods. It doesn't make everybody happy but everybody knows where they stand.
Unofficially, all sorts of people with all sorts of Linux distribution chance their luck here. Unless they mention their respin explicitly, it's unlikely a question would be booted off.