I'm afraid this speculation is absurd. On the contrary, the tendency here is to return to a more historical orthography (par example: Mr Babiniotis the professor of linguistics at the Capodistrian Univ of Athens has proposed to return to the aspiration marks and especially to the spiritus asper in order to end the confusion between the aspirated and unaspirated pairs of plosive consonants. For instance, why do we today use "μεθεόρτια" (metheortia-relig. octave) instead of "μετεόρτια" (meteortia) since we have stopped using the spiritus asper on the word ἑορτή?).
PS: Proto-Greek or prehistoric Koine has nothing to do with a more simplified Greek language. Quite on the contrary*. Proto-Greek is the common ancestor of all the classical Greek dialects (Attic-Ionic, Aeolic, Doric, Arcadic-Cypriot, Macedonian, Pamphylian) spoken in the late 3rd millenium BC. The only written evidence of this language is Linear B.
*Proto-Greek had 5 long and 5 short vowels, the labiovelars w (wau) or F (digamma) and y (yod), the vocalic (ie letters who could appear as either consonants or vowels) μ, ν, λ, ρ (m, n, l, r) etc. Not a simple language