Yes and No; because honestly shoehorning a homosexual character into a kids show for the sake of having them in there can only end badly especially considering the quality of the shows usually held to by the companies that publish them.
Writing in a homosexual character is perfectly fine though as really nothing would change; unless you had an episode about relationships which, depending on the target age group, would happen anywhere between never and rarely (or every episode if the demographic's 'tween'). There's a reason the only place Rainbow Dash exists as a Lesbian is in the diluted minds of shippers; because the show's about friendship magic not relationship magic.
Writing in a homosexual character is perfectly fine though as really nothing would change; unless you had an episode about relationships which, depending on the target age group, would happen anywhere between never and rarely (or every episode if the demographic's 'tween'). There's a reason the only place Rainbow Dash exists as a Lesbian is in the diluted minds of shippers; because the show's about friendship magic not relationship magic.