Allegory is one kind of evidence, arguably one of the most obvious sorts of evidence. It’s not the only kind though. I have never played the Hollow Knight games so I didn’t know those facts you just mentioned. Still, from what I’ve seen of the games in screenshots, I get a vibe.

Perhaps part of it to me is that the protagonist is non human, barely even resembling anything humanoid? There’s also a gloominess, a loneliness to it.

Not saying these vibes are in any way a perfect diagnostic. Heck, I wouldn’t have predicted the announcement beforehand. But in hindsight it feels right.