The SSPX bishops still don't know that there was a precise doctrinal mistake made by the contemporary Magisterium. A wrong premise and inference was used,in the interpretation of Vatican Council II. It resulted in the rejection of the Council by the SSPX.It was followed by the excommunication of Archbishop Lefebvre and the SSPX bishops over this doctrinal issue.
Since 1949 the contemporary Magisterium is in heresy and the sedevacantists and traditionalists are correct doctrine-wise. Due to the Magisterial Heresy, there is a break with the 'perennial Magisterium', the pre 1949 magisterium.
Pope John Paul II made a doctrinal mistake. He used an irrational premise and inference to interpret Vatican Council II and wanted Archbishop Lefebvre to do the same.
He was interpreting Vatican Council II with irrational Cushingism instead of traditional Feeneyism.He was using the irrational right hand column and wanted the archbishop to do the same.
The traditionalists and sedevacantists at that time were also using Cushingism, the irrational premise and inference and the right hand column to interpret Vatican Council II- and they rejected Vatican Council , while Pope John Paul II accepted it.
Cardinal Joseph Ratzinger , Prefect of the Congregation for the Doctrine of the Faith(CDF), instead of clarifying all this,made the same error and then approved the excommunication.
This was Magisterial Heresy since they were rejecting the dogma extra ecclesiam nulla salus, defined by three Church Councils.They were rejecting the Nicene Creed ( one baptism for the forgiveness of sin and not three) and the Athanasius Creed ( outside the Church there is no salvation).They were rejecting a Vatican Council II which is really traditional and in agreement with the old ecclesiology.
Today if the SSPX and the sedevacantists accept Vatican Council II interpreted with Feeneyism, the Left Hand Column and without the irrational premise and inference, they can still hold on to the old ecclesiology.They do not have to reject Vatican Council II.They can have it both ways.It can be Vatican Council II and the old ecclesiology.
The SSPX should ask the CDF for an apology on this issue.The CDF was not fair to Archbiship Lefebvre. It was their responsibility to explain what was correct doctrine.