I didn't. Trumps executive order is explicitly cisgenderist, but trans people are not a third gender.
You need to add that "gametes" stuff for it to invalidate gender transition. Like, even TERFs made this point only in the recent years. This is not to mean that the "2 genders" adage is trans-accepting, but it does not exclude trans people by itself, as it literally does with intersex and non-binary. It is the shared set of beliefs that makes it such the transphobic slogan, and before "gametes" it could be a number of other things - like gender essentialism.
People who say "we accept all genders, we let trans women into the women's toilet" are in fact third-gendering trans-people. This is IMHO problematic, and people with your or OPs record of curating trans-related journalism should be aware of it.