Joseph, I have certainly heard people use that term as an honorific for contemporary Gedolim in my lifetime. However, I do not think I have ever heard anyone use the term in its literal sense. Rav Moshe was widely accepted as the Torah authority for the yeshivish velt in the United States. But he was not accepted as such an authority by the Chassidishe velt or even the Yeshivish in E”Y.
The same is true of Rav Shach (who was never really treated as a halachic authority) and Rav Elyashiv. Their sphere’s of authority were limited to certain subsets of Torah Jewry.
Even the Chofetz Chaim, who was universally revered as a tzaddik yesod olam, was not viewed as an authority by all Torah Jews. Even Rabbeinu Gershom Meor Hagolah, was not really a Rashkebahag because he was not followed in the Mizrachi world.