Understood, but when Christ spoke to John, would He speak in Greek or Hebrew? Both were Hebrew. Why wouldn’t He speak Hebrew to John?
Jesus would speak Hebrew to John, but John wrote Revelations in Greek. All the manuscripts of Revelation are in Greek. As has been said, it was the lingua franca of the time.
The Holy Scriptures are "God-breathed," written in the languages of the writer, inspired by the Holy Ghost.
Moses wrote Torah in Hebrew, as was all the rest of Tanach save Daniel Chapters 2 to 7, which (written to/about Gentiles) was in Aramaic.
What we call "The Old Testament" was written to, and for, the People chosen by God as His Own.
When Jesus fulfilled the Law, and ordained the Gospel of salvation and reconciliation be proclaimed as a herald to the Jews and Gentiles alike, The Holy Ghost caused the Scriptures to be written in the common (Koine) language of the day, a very precise tongue making His meanings clear to the Gentiles.
The very first writings of the Gospel of Matthew (Levi) are supposed to have been written in Hebrew or Aramaic, appropriately because that Gospel was directed toward the Jews and their culture. But that Gospel was not preserved, not canonical. As written (or rewritten) by Levi, it was cast in the Koine by inspiration of the Holy Ghost, and preserved for us today.
Whatever language John's thoughts may have been formed in, he chose and wrote the words as ordained by God in Greek, and that is without question the language that John wrote his works in, and John's writings were directed to everyone who spoke and read the common Greek then used for everyday communication.
The Holy Ghost would not have spoken to John in Hebrew, expecting fallible John to translate and interpret the Hebrew into Greek. No, God spoke to and formed John's thoughts in Greek, that we might have His Thoughts directly given in the beauty of the rich, descriptive terms of the language, with its grammatical precision, that we might know exactly what God wanted us to understand.
The information which may come out of the numerals representing a number of six hundred, sixty, and six were transmitted in Greek so that anyone with basic intelligence could figure out what God/John wrote without getting him sent to jail on the basis of openly demeaning the Roman leaders by name.
It was not written as some kind of mysterious abracadabra numerological idiocy that required knowledge of Hebrew and Jewish culture to even reconstruct some kind of hidden meaning.
I don't think your approach in this article makes any sense at all.