It's been around for a while. "Viewpoint diversity" has been on the rise since the early 2010s at least, especially among thinktank Republicans and the intellec

It's been around for a while. "Viewpoint diversity" has been on the rise since the early 2010s at least, especially among thinktank Republicans and the intellectual/philosophical fringe of the liberal elite. I recall hearing the phrase a lot in the context of overbearing DEI initiatives (now commonplace) that were criticized for being too superficial in their concern with diversity of "race" rather than diversity of opinion.