What is problematic about this line is that no such “message” appears in Humanae Vitae. Of course, the interim report was written hastily and perhaps there is a bit of sloppiness of expression here, for it seems to state that the dignity of the person means that the person has the freedom to morally evaluate the methods of birth control. And “moral evaluation” here seems to mean, “has the right to decide which methods are moral and which are not.” This interpretation seems to follow one that was advanced by many theologians after Humanae Vitae that stated that spouses were free to do what their consciences dictate in respect to contraception. Whether that is what the authors of the interim report meant or not, it is surely not a concept present in Humanae Vitae. The conscience, of course, is not the same as our opinion or judgment about whether a certain kind of act is right or wrong.
This document is so full of garbage, you’d could create a market for shovels on it alone.