Now, do we know they identify as a he? I think we should be respectful and not make any assumptions about them. They are wearing the women's costume.
We're only saying he because of the mustache, a traditionally male trait. Which means this person might have been mis assigned as a male at birth.
So I would make the argument that anyone here referring to them as a 'he' is, in fact, tied to the gender binary. I think we definitely have a long way to go when discussing this stuff, but unless anyone knows the Cast Member and how they identify, we shouldn't assign any pronouns.