something about toby fox and queer narratives is that i think often, at least in my eyes, toby fox is just a guy who may or may not be queer himself who simply sees queerness as utterly Normal and something that doesnt really need to be written on the walls going "THIS IS QUEER BTW!". and sometimes this really works out because it means its obvious hes not really thinking of his gay couples as, like, anything that needs to be more clear than his straight couples, and normalization like that is good and what we want.
and sometimes it really doesnt work out because it means despite the fact that kris is obviously nonbinary and understanding that is important to understanding their narrative.... toby is likely never going to say, outright, that kris is nonbinary. he'll correct pronouns of characters, but he wont Say hey, this character is nonbinary, not a girl or boy.
and i think its good to, like, acknowledge that that kind of sucks and makes it hard for nonbinary fans of undertale and deltarune sometimes because toby isnt really working with us. and this is kind of a pitfall of writing where both in and out of character theres no usage of queer terminology in the effort to see queerness as something normal that doesnt need to be emphasized.
because where we are in society Right Now, is a time where it isnt enough for a character to just be constantly referred to with they/them. you do have to confirm something, or else you leave nonbinary fans of your work floundering against a bunch of transphobes who wont take anything less of outright confirmation as an answer. and that just sort of sucks!