You're afraid to be corny, but I was born on the cob

Honestly, I don't think that Kris being nonbinary invalidates the idea of the Weird Route being a metaphor for compulsory heterosexuality. Nonbinary people can play the part of binary genders, socially speaking, even if that doesn't match with their internal sense of gender.

Even aside from that, I also don't think that the genders have to line up with what you're commentating on in order to be effective commentary, either. Het couples can be queer-coded within their story.

Also the majority of people I see getting angry at people who interpret this NB/F relationship as a commentary on male/female relationships are the exact same people who call that same NB/F relationship "yuri" so, like. You can't have it both ways, you know? Either it's erasure to see Kris as a gendered figure for the sake of viewing their relationship with Noelle in a certain way, or it's not. (And saying that it's a comphet metaphor doesn't even imply that Kris fully is a boy, just a metaphorical stand-in for a boy.)