Also, Communists were for contraception. Patriarchate of Moscow allowed the pill in 1970's. Pius XII allowed periodical abstinence in the fertile periods. They broke with the past and with each other there.
ROCOR, notably Fr Seraphim Rose, opposed the Patriarchate of Moscow on precisely these two, among other accounts. Pius XII not only helped Wojtyla, but also Ratzinger to become famous theologians bending down to fashion - and later bishops and popes. The problem is: after two evolutionist popes, evolution starts to feel normal for Catholics, just as it feels normals for the Orthodox adhering to clergy until recently under Communism. And so do the deviations from traditional marital practise which not only is against pill (et c) but also for periodical abstince precisely the other way round, in infertile periods - when both spouses agree - or unrelated, when it is for prayer - like nights before a Sunday (especially if receiving Holy Communion) and so on.
But if deviation from the normal feels normal on both subjects and because ultimately of Communist persecutions ... how is truth being kept in Church? It seems to me, small groups on both sides of the schism preserve truth intact on both these issues. And both Paul VI and a recent Russian synod each preserved their half of the truth in what they condemned: the pill and the periodical abstinence imposed on the other spouse for sake of contraception. But Vatican and Moscow still feel evolution as something normal for a Christian to believe. Which it is not.