""Betrayal" is the only word I can think of right now..."
Betrayal seems an odd word to use. Since the RCC already accepts evolution as the way species developed, then they're simply clarifying the issue in the face of those who would have the creation story from Genesis as literal truth.
Sorry, but you'll find that most Christian denominations accept evolution as the means by which species came about. Not all, but most.
Chapter and verse please.
The Church explicitly rejects materialistic evolution but permits belief in theistic evolution. Catholics are also permitted to believe in Creationism. Catholics are only required to believe that the human race has descended from an original couple --Adam and Eve.
HUMANI GENERISENCYCLICAL OF POPE PIUS XII
CONCERNING SOME FALSE OPINIONS THREATENING
TO UNDERMINE THE FOUNDATIONS OF CATHOLIC DOCTRINE...Venerable Brethren,
Greetings and Apostolic Benediction...5. If anyone examines the state of affairs outside the Christian fold, he will easily discover the principle trends that not a few learned men are following. Some imprudently and indiscreetly hold that evolution, which has not been fully proved even in the domain of natural sciences, explains the origin of all things, and audaciously support the monistic and pantheistic opinion that the world is in continual evolution. Communists gladly subscribe to this opinion so that, when the souls of men have been deprived of every idea of a personal God, they may the more efficaciously defend and propagate their dialectical materialism.
6. Such fictitious tenets of evolution which repudiate all that is absolute, firm and immutable, have paved the way for the new erroneous philosophy which, rivaling idealism, immanentism and pragmatism, has assumed the name of existentialism, since it concerns itself only with existence of individual things and neglects all consideration of their immutable essences.