I’ve posted the statement from the encyclical numerous times. What Pope Pius XII has done in the past does not contradict Pius XI because the former pope’s actions concerned science matters and the latter pope’s actions concerned moral doctrines.
You seem to believe that interreligious meetings on agreed moral doctrines is something that either one of them would condone. Please offer evidence that either one would do so.
switch latter with former
That is of course not to say that Pius XII thought that a Protestant geneticist has some kind of Magisterial moral authority. The point is, Pius XII was intelligent enough to consider the experience, training, and insights of an intelligent man of good will who happened to be Protestant.
Back to the topic at hand: Bravo to the Humanum pro-Marriage group, Catholics and non-Catholics alike. They can make their positive contribution wherever intelligence/good will can get the respect it deserves.