First of all, what I referenced are the site's definitions for tags, not my own. They are included in the rules section.
If you're going to describe bestiality as sex with an animal, then sex between to humans could be included as it's two animals. The female characters in this clearly fall under neither monster girl nor furry (as they have zero anthropomorphic characteristics, fully pony anatomy), thus it would be sex between a person and an animal, albeit an intelligent animal. When people look for content with bestiality, I seriously doubt they're thinking about if it's with something of a low enough intelligence and more about if it's with something that has animal sex parts. Pretty sure this is a clear case of needing a bestiality tag.
Is it though? Ignoring the holes, your argument still depends on your definitions of 'animal' and 'person'. If we disregard any other criteria, go by kindergarten logic and only take into account shapes and forms, then sure the love interest characters look somewhat like animals.
We still never see a full rendition of the MC though, so by the same logic we can't 100% identify it as human.
Since in most places only humans are considered people, the game still fails the site's definition of [A sex act between a person and an animal. (Not monsters, aliens...).]
On the other hand, if you consider the love interests 'not animals' because they are intelligent, then they can still fall under the definition set by the Monster Girl tag, since there are no requirements about the anatomy of the monster girl in it.
Just because the ponies resemble animals more than an orc, a lamia (half snake) or a drider(half spider) or doesn't have human parts shouldn't matter. The illustrations are still far enough from actual animals to make a clear distinction. If you saw them without context and ever knowing about MLP, then figuring out what the fuck they are wouldn't be obvious. (based on personal experience with old people)
What people think when they use the search function is irrelevant, since what is common sense to one is nonsense to another. The only common resource we can rely on is the site's definitions, but they are pretty much
half-assedly thrown together dated, and cause as many issues they solve.
(khm NTR khm) Best we can do is ask for clarification from a higher power, and rely on their judgement.
To be fair, I don't mind the bestiality tag for the game - and yes, I agree some folk would find it easier - it was just amusing to ponder the issue a little.
