The Church regards itself as a kind of club, with rules of membership. Like any club, it is bound by the law of the land; in this case it wouldn't, probably, be breaking the law if it discriminated against homosexuals in this way. The government is not of a mind to find out.
We don't have to be members of the club. A club whose constitution and purpose is for one sex only, or one religion or specified groups within that religion, may exclude those who are not within that. It would be absurd if a woman complained that she was not admitted to the membership and practices of a male voice choir which was constituted as a club. It would be absurd if homosexuals insisted on participating in the practices of this club, in so far as it has rules and is constituted against their being admitted to them. Since they do not, the question should not arise..