Unfortunately, the quotation given from YouCat 421 gives further cause for concern. It reads:
421 Why are all methods of preventing the conception of a child not equally good?Both the question and the answer fly in the face of everything that loyal Catholics have done to promote the teaching of Humanae Vitae.
The Church recommends the refined methods of self-observation and natural family planning (NFP) as methods of deliberately regulating conception. These are in keeping with the dignity of man and woman; they respect the innate laws of the female body; they demand mutual affection and consideration and therefore are a school of love. [2370–2372, 2399]
The Church does not say that contraception and natural family planning are "not equally good." It teaches that contraception is a sin (not a lesser good), while NFP may be a morally acceptable means of limiting the size of a family if there are serious reasons for doing so.
The Church does not "recommend" NFP as though artificial contraception were a less perfect option. Nor, in fact does it consider NFP and contraception to be the same kind of moral action. This is one of the basic elements of apologetics in support of the moral teaching of the Church: contraception is definitively closed to the gift of new life, while NFP recognises that new life may be less likely at certain times.
The composers of YouCat have made a classic mistake in their attempt to appeal to young people. A question and answer such as 421 above, looks like an attempt to put things diplomatically: to water down the teaching of the Church in case it is too difficult.
In fact, the young people who are still willing to listen to the Church want clear, unambiguous answers. On sexual ethics, they may fail to live the natural law as clarified by the Catholic Church but they will be willing to repent and come back to Christ in humility. As a priest working in perhaps the most secular corner of the planet, I am only too well aware of the import of the modern translation of Psalm 118 "How shall the young remain sinless?" The answer is "by obeying your law", not by waffling around in timid appeasement. (As I highlighted the other day, Waffle should only be served with syrup.) The last thing young people need is for priests to fudge what are crucial questions for their everyday lives.
YouCat has already earned the nickname LolCat. If the stuff on contraception is so muddled, what will it be like in other areas of theology? I await the published edition (released today) with some trepidation.