Idk, this seems like something no one should really be upset with. It’s the same as misgendering a cat. It doesn’t really matter, the cat has no concept of gender.

Yes, ignoring your child’s gender identity or trying to reinforce societal norms that run counter to how they present themselves can be harmful. But until a human starts forming their conceptual idea of gender, I don’t really think it’s insulting or harmful to utilize gendered language simply out of convenience. That’s unless you want every single conversation to be about the gender identity of someone who hasn’t developed a gender identity.