Papal teaching on contraception has developed since Humanae Vitae (1968). In “The Joy of Love” Pope Francis does not label contraception as going against natural law or being intrinsically evil. He seems to acknowledge that exceptional circumstances can make contraceptives licit.
The main achievement of “The Joy of Love” is that it officially re-affirms conscience as as the ultimate judge for the individual on what is right and what is wrong. This he also applies to contraception.
It remains regrettable that Pope Francis could not take the final step and abolish the official total ban of contraception.