How many Disney movies has your child watched? Heteronormativity is 100% prevalent in nearly all media.
You don't even have to single out Disney, 99% of popular media will present heterosexual relationships as the norm, and children's media that shows something as benign as a same sex couple holding hands or hugging is viewed as mildly transgressive or at least newsworthy.
Gender non-comforming behaviour is 100% absent outside of maybe a "tomboy" female character (and even that seems less present than it used to be).
You don't even have to single out Disney, 99% of popular media will present heterosexual relationships as the norm, and children's media that shows something as benign as a same sex couple holding hands or hugging is viewed as mildly transgressive or at least newsworthy.
Gender non-comforming behaviour is 100% absent outside of maybe a "tomboy" female character (and even that seems less present than it used to be).