just a matter of time before another 'revelation' is forthcoming when the day comes that the Mormon Church will allow gay marriage.Yes, I really think so, but not under current law of course. The real issue here is tax exemption, and when the IRS decides an organization is no longer serving the general community interest and revokes its 501(c)(3) status, that's the sort of thing that causes revelation to happen.
That is exactly what was happening in 1978 with Bob Jones University and its admission policies for black students. The Supreme Court eventually upheld the IRS's decision that racial discrimination could be cause for revocation, on the grounds that tax exemption carries a cost for all tax-payers.
In the distant future, if Mormonism survives at all (and I think it will), there will be female bishops, gay couples in full fellowship, and temple weddings open to nonmembers. But only when the community conscience makes it inevitable. God's one true church has not exactly been a trailblazer in the civil rights arena.