Yes, it’s true that the Oblates own that property on which the parish sits, but the Archdiocese can disassociate itself from that parish and tell everyone why, thereby providing a clear break

Write a pastoral letter. “Dear Faithful: It has come to my attention that there is a convicted child molester on staff at St. Joe’s. Canon Law does not allow us to act. Please stay away. Don’t go to this parish. ”

We might have to go to the secular press to get action. There are frothing cathophobes who’d love nothing more than to make hay with this, but if nobody is going to budge, we have to make them.