Reminder that Toby has never referred to anyone in Undertale or Deltarune as “non-binary”. Some species in those games, including humans, are literally genderless in the same sense that legendary Pokemon are genderless. Both games do this to reinforce the twist that you’re not actually controlling who you think you’re controlling (in Undertale, the protagonist and the character you name at the beginning are two different characters, while in Deltarune, you play as the human soul that’s controlling Kris, but Kris can break free from the soul and, by extension, your control). By leaving it ambiguous, you’re meant to self-insert yourself as the main character, which makes the revelation that you’re not actually playing as that “self-insert” more impactful.