That says nothing about denying the Resurrection - just that Kasper considers the tomb stories unhistorical.
It is Fr. Harrison who argues that Kasper's premises lead to the denial of the resurrection and virgin birth - he doesn't cite Kasper on that because Kasper affirms the resurrection and virgin birth in this book!
Reread the piece. Kasper denies miracles happen. That includes the Resurrection. The whole tenor of the Harrison piece concerns the Resurrection and its denial by Bredin and Kasper.