If you have not had a careful reading of Humanae Vitae, by now Saint Paul VI, that would be very important. “They” are the Mystical Body of Christ - which has the authority to give teachings that don’t “maybe need to be reconsidered,” which this moral question clearly falls into. If this doesn’t fit the bill for “ordinary magisterial teaching of the Church on morals,” (an infallible category of teaching) then nothing does.
Contraception is not a little pecadillo - and its long-term effects on individuals, families, and societies are nearly unimaginable. It is easy to see for those who wish not to be blind to it. The pill came, then no-fault divorce, then abortion, then gay pride, now transgender mania. Do you see the progression? It starts with trying to remove the necessity of having to face the possibility of lasting consequences for sexual acts, and it builds from there into a complete destruction of even the biological reality of sexual differentiation and permanence at all.
Simply not having relations when pregnancy is foreseen is a “non-act” rather than a willful distortion of the sexual faculty. It is very different. However, there is a mentality that also can warp NFP… there are dragons here too - but they are smaller.