I've noticed that when a story has meta elements, some fans try to interpret it as if there must be a "strictly in-universe" explanation.
Like the straightforward interpretation of the Soul in Deltarune is that it's the player, in some sense, or at least that there's some kind of connection through the fourth wall. The first time you save in chapter 1, you overwrite a save file named "Kris" with one with your own name. Maybe Toby Fox will make it more complicated than that in coming chapters, but you can't really assume he will. You can't remove the "it's the player" interpretation from Deltarune and still have it make sense because the story which Toby is in fact telling us appears to be one where it is the player.
Feels like another manifestation of treating fiction like a documentary of things which "actually happened somewhere", instead of a story which was constructed with intent. Eh.
