"The Church will not ask, but if someone comes out of the closet, he is out."
Well, not exactly. If he makes it to ordination - even if he has to lie, deceive, or is in-correctly guided, then there is no "outing" either physically, or by sexual orientation once he is a priest.
And currently there are no canonical penalties or consequences for being a homosexual priest or bishop. They can (and they have already) reach (reached) levels of absolute power and control in the hierarchy.
The instruction is a significant step, a necessary one, but it is just one step of several that need to be made.
Something is seriously amiss then. Obtaining holy orders on a lie is like conscrating the Eucharist without believing in the Real Presence: both are spiritually void of any validity.