I feel like educating younger kids about people with nonbinary identities or the LGBTQ+ community in general is a good way to keep them from growing up to be hateful towards those kinds of people because they don't understand them and in the future, to keep them from feeling super confused if their identity doesn't fit in with the "norm". Kinda similar to including people of color in a show, it's probably just to make sure kids grow up to be accepting and understanding of others despite their differences, it doesn't matter what their age may be, it's not really doing much harm if kids are informed that those kinds of people exist and that it's okay that they do.
