No, a protasis is not a revelation; it may presuppose one and it may hope to invite to one, but by itself is not a revelation. If it was, there would have been no blind and deaf people. If it was a revelation by itself, getting everyone into a class and teaching them about God would be enough to make them believe. The contrary happens now; teaching about God to indifferent persons produces contempt for the Word of God, which is the reason that the Bible consults “do not throw the Holy to dogs”.
A protasis of course includes a metaphysical aspect, or rather it is metaphysical essentially, since nothing physical by itself can explain the formation of a language. There exist various secondary influences, but not an efficient and primary causality in the grounds of a language. The fact that the Greeks created the Greek language and Tatars a rather different one, can not be explained by reference to physical causes. It is a spiritual creation and a mystery.
Cf. Elpenor’s Greek Language pages