Ah, but the Church's teaching develops, all the time. Some bishops are discussing a very relevant topic. I think it's worth a discussion, even if the teaching isn't adapted to the circumstance.
But in the development of doctrine, a new understanding never contradicts an old one. So, to say that using contraceptives under certain circumstances is not a development of doctrine, but a corruption. John Henry Newman explains this in his classic work ON THE DEVELOPMENT OF DOCTRINE.
I know that Newman isn't as "relevant" as Hans Kung, Richard McBrien and Edward Schillibeck, but he does have some excellent insights from time to time.