What an interesting read. Tbh I never paid much thought about how ancient scripts might have been deciphered and it is even more awesome than I would have anticipated.
One thing that is not clear to me, however: The text says
Because Linear B is a syllabary, and not an alphabet
The text does not go into detail about how this could have been known to the researchers. Anybody got a hint for me here?
By the number of different glyphs that you find. Alphabets and abjads typically have 20~30 glyphs, syllabaries around 80~200, and logographic systems have at least a few hundreds.
That's also how we know that the Voynich manuscript is written in an alphabet, even if nobody deciphered it yet.