By the way, are all people who make heretical comments in private conversations automatically not Catholics? Is there some kind of rule about automatic self excommunication?
Those who want to destroy the Catholic church and thing Jesus was an Aryan and don't believe in transubstantiation are not Catholics.
There is indeed. It is called excommunicatio latae sententiae, when one commits an act that is so obviously an act of apostasy that no court of canon law needs to convene in order to explicitly declare an excommunication.
Hitler engaged in several activities that automatically excommunicated him, including his participation in meetings of Karl Lueger's anti-Catholic Guido-von-List Gesellschaft.
The passage of the Nuremberg Laws also incurred an automatic excommunication, since anyone who is responsible for crwating and enforcing legislation that voids or impairs the laws of the Catholic Church regarding sacramental marriage are excommunicated.
He was automatically excommunicated for the procurement of abortions of women considered unfit.
He was automatically excommunicated for depriving the Church of its liberties.
There are various stories of his personal life which, if true, also create conditions for various automatic excommunications.
When he ordered the killings of various priests in such places at Mauthausen, he cemented his various preexisting automatic excommunications many times over.
The list goes on and on and on.
Few people ever baptized Catholic have ever incurred more automatic excommunications than Hitler.