Thank you for highlighting another side of the issue.  May I try to add a note of clarity (and keep it brief)?  The fact is that true dogmas of the Church (and there are really only three- the rest is doctrine which is what has changed at times) are not changeable.  The divinity of Christ, His Death and Resurrection, and the Assumption of Mary are dogma and not subject to interpretation nor alteration.  Doctrines are the layers and layers of Church laws or Teachings that are undergoing questioning now.  Doctrines have changed: one good example is the law that lay Catholics were never offered the Cup at communion, starting in 1416, and remained unchanged until Vatican II.  And another one is that no pope was formally declared as being infallible in teaching until 1870.
This is why the doctrinal purist have fallen into such disrepute.  You can read all about this in many volumes and on-line via a Google search.  Disregard that "unchanging"  blabber...it isn't true.