Answering Msgr. Pope's good question
It's an attractive idea, at first glance, but it stumbles pretty quickly, I fear.
First, it's not Catholics who need to find a new word for "marriage", rather, it's social engineers who need to find a new word for whatever exactly it is that they think 'same-sex marriage' is meant to be; in any case, they should stop co-opting our perfectly fine term.
Second, it falls to the Church to protect true marriage not just for Catholics but for all human beings; the plain fact is, however, the great majority of true marriages in the world are not sacraments (because the parties thereto are not baptized), hence, most truly married couples are not in what may be called "holy matrimony." It wouldn't do to protect "holy matrimony" while abandonning true marriage to the machinations of secularists.
So, okay, maybe this particular solution to the crisis in marriage won't get us very far; but that doesn't mean that the sort of radical steps that monsignor has in mind aren't needed. It just means that he needs to keep on helping us find and refine those solutions.