Are you saying that to reject the Holy Spirit even to the moment of one’s death is NOT Catholic teaching? If Jesus knocks at your heart’s door and you deny Him entry and say, “I don’t believe in You. I don’t need You. Go away.” and you continue in that vein to the moment of your death, that is not Catholic teaching?
You see, I was always taught that the Unpardonable Sin was blasphemy of the Holy Spirit and rejection of Jesus which includes things like rejecting Jesus’ invitation to be your Lord and Savior, rejecting the Holy Spirit Himself and crediting those things that come from the Holy Spirit to Satan.