There are more than a few errors in this article. St. Theresa Benedicta was not a universalist. Nor was von Balthasar. The latter spoke of the possibility that hell is empty and asked if we may hope it to be so. To my knowledge, Cardinal Ratzinger was not one of the principal authors of the new Catechism; Cardinal Schonborn was the general editor, and Cardinal Ratzinger headed up a bishops' commission that had oversight, but to make claims about his specific views from what does or doesn't appear in the Catechism is incorrect.
Article: "Hans Urs von Balthasar, who was a universalist—that is to say, he believed that Christ’s salvation was universal. According to that view, if there is a hell, it is empty."
I think we're jumping logic here. To believe that Christ's salvation was universal is not the same as believing every single soul actually makes it to heaven. Yes, Christ saved all men and women by the events we're about to commemorate this coming week of Holy Week. In that sense, it is universal. But where there is human freedom, salvation is not 'automatic': salvation isn't universally applied. We are given the chance, we're not forced into it. I realize this is simplifying theological issues but I think this is as condensed as I can make it. We could go into freedom, individual consciences, and all that but maybe you should really review the Catechism again and look at the citations (the references are a brilliant part of the text).
(On a side note, I still think Dante was right in including the inferno in his Comedy. I know there's been a lot of hoopla about the pope speaking about hell recently but that really shouldn't be anything new to educated Christians.)