Very interresting post and you can never say too much. I suspect that the mystery of tongues has already been unraveled and Zephaniah 3:9, reference by your post is a prophecy declaring it.
For then I will restore to the peoples a pure language, that they all may call on the name of the LORD, to serve Him with one accord. (NASB) Zephaniah 3:9
Some biblical scholars think that Hebrew was the universal language before the flood and that Hebrew was reserved for the use of the ancesters of Abraham after the Tower of Babel event.
There is some evidence that during the millennium five cities in Egypt will be speaking Hebrew:
18 In that day five cities in the land of Egypt will be speaking the language of Canaan and swearing allegiance to the Lord of hosts; one will be called the City of Destruction. Isaiah 19:18
The Revival of the Hebrew Language | Jews | Lamb and Lion Ministries (christinprophecy.org)
An insightful comment yet fraught with danger, especially for me. The Biblical Hebrew that we know is part of the Semitic family of tongues. I cannot say that it is the pre-diluvian language - there is Assyrian, Accadian, Babylonian and Aramaic, to name most prominent of them. However, Biblical Hebrew is almost supernatural to a linguistic scholar like myself; by applying some of the mystical techniques used by ancient rabbis, incredible spiritual insights can be derived with study.
There can be no doubt that Biblical Hebrew at least reflects the language of Noah and his forebearers. The danger I encountered was using the mysteries of Biblical Hebrew to attempt to decode the scramble of Babel. Great evil power lurks there, power that today's evil societies are working mightily to unlock. When I realized that, I realized that I did not want to be the one to decode Babel.
As for Zephaniah 3:9, it is a language of pure truth, lacking any capacity for lies or deceit. The antichrist cannot survive in that atmosphere and so I tend to associate it with the Rapture. The unraveling of the work of Babel will, in my view, usher in 'the tongue of the Egyptian sea' - all the world will once again speak one language ... and do evil.
Harari knows that the only way to establish a one world hegemony is to undo the work of Babel. I doubt that Klaus Schwab is that instrument.
I just got to your link - sorry for the delay. Interesting; I will have to spend some more time with it. Obviously I have some differences of view {re: Zephaniah 3:9 - which could infer more than one meaning} but it is worthy of further study. I was careful in my earlier reply to specify 'Biblical Hebrew' {Masoretic Text & DSS} in contrast to Israel's modern spoken Hebrew when thinking about the pre-Babel language of Noah.
Later...