That's a very surface-level interpretation of what is depicted in the show, or at least, what was depicted in the show in whatever prime. This is one instance where normies are dumber than the analyst spergs who were drawn to this show and made an altar of it.
Lauren Faust and co. probably weren't going for anything very complex that catered to people who have ended up having some or many /pol/-esque anti-globalism, anti-multicultural diversity views; in fact much of us who are drawn to that who are also MLPFiM fans were still in our redpilling process/at various stages of it depending on each one of us personally, when we got into this show.
"Bridle Gossip"'s anti-prejudice or whatever message sure doesn't relate to the arguments that are supposed to combat the type of racism* that we find ourselves doing in the contemporary West.
*I don't put that in quotations because I'm not being skeptical or sarcastic about that. If that's the word that is to be used about young, mostly-white people in North America and Europe taking notice of what is going on around us, so be it.
MLPFiM drew us in because it depicted this idyllic, imperfect-but-happy setting with mostly decent beings. That setting was never "multicultural" or multicultural or whatever.