I don’t know if the elites would lose a language ability they once had since it was the elite who controlled the rituals and needed the language. But, who knows...?
I know that I can go into a Reform and Conservative synagogue now and a bunch of the service will be in Hebrew even though very few there, even those controlling the rituals, are fluid in everyday Hebrew vernacular.
The non-Biblical texts among the Dead Sea scrolls, mostly in Hebrew, also indicate its use as an everyday language past the Temple’s destruction.