Really?
It comes from the link in the great=grandparent, to the text of Humani Generis.
The Catholic Church does not work the way you seem to think it does. They have made perfectly clear that polygenism is now acceptable, even without making a "new statement" in the way you that you suggest. And even Pius XII was deliberately suggesting the same thing in that very statement, by saying "it is in no way apparent" that a reconciliation is possible, rather than saying that one is not possible.
Another month, another rationality quotes thread. The rules are: