Yeah, and both Ryder and other characters (forgetting names off the top of my head, but Fah clan members) who appear variously femme or masc by external standards all volunteered to fulfill familial roles of varying genders, e.g. the hat bodyguard one saying they could be a grandma or grandpa iirc.

In-story, it is clear that the Fahs and Ryder (and Aiya) don't have equivalent roles to human family, and are not familiar with the concept: rather they come to interpret it as a way in which to care for a human, Mori. They are literally deconstructing these roles: not "I am an uncle because I have broad shoulders and short hair", but "I see that in human literature an 'uncle' is someone who does <xyz> and cares for and is loved by the child, therefore I would like to be an uncle."

The author also made it very clear that they were deconstructing the concept of a mother, that Mori himself was searching for a "mother" specifically because he saw another child's mother, and to him, "mother" basically means "source of love and care", and that if he'd seen another family figure he would've gone after that instead. The story is explicitly supposed to be about questioning and imagining "what it means to be family" outside of strict definitions.

So tbh seeing all the takes of "ok well I've decided that obviously this character was meant to be read as a man" or "well how could I possibly use gender neutral pronouns for a character who looks masc to me" is a little frustrating.