AAQ
Regarding your question that this is too subtle “ CS > Beis Moshiach is gematria 770”
You’re welcome to learn the sicha of shoftim 5751 in sefer hasichos where The Rebbe says that he’s saying higiah zman geulaschem as a navi. I have learned it but haven’t yet looked up all the footnotes in nigle sources etc.
Nevuah is supposed to return towards the end of golus/ towards the start of geula.