>>36783334>1. Replace names, visual descriptions and species of characters
Those are literally the most defining characteristics of the setting. Do you mean visual descriptions of characters, or just visual descriptions in general? Either way, this is retarded.
Half the episodes in the show itself would be practically "not MLP related". The one thing left if you do that is the general tone of the story, and potentially the setting/worldbuilding lore. Tone doesn't identify a franchise, and again in the show itself there are multiple episodes that don't even belong in the show if you remove all pony context; moreover, fanfiction doesn't follow the "happy land where you learn friendship lessons and plot armour guarantees no bad consequences whatsoever". In fact, good fanfiction will at least have decent stakes for its plot, even if the core message remains "friendship lessons"; but there's a huge amount of excellent fanfiction that strays from rigidly adhering to the tone.
The remaining thing is the worldbuilding. You're saying having the exact same worldbuilding and cosmology as the show is more important than the characters, the species, and the setting. This is exactly what makes your take retarded.
That being said, Pirene is definitely an extremely far removed AU. It's still MLP fanfiction due to prominently featuring MLP characters, but there's no argument that it's quite far removed from the tone of the show. It's just your metric that's complete shit.