So, the question -- who is the vector that converted the Habermasian and institutionalist definition(s) of social media into the technological one? I suspect the person was probably not a sociologist or critical social theorist, but a college educated techno entrepreneur who had become acquainted with such ideas in school, and who either consciously or unconsciously siezed upon this phrase for the new context.

There seems to be evidence to support the idea that there existed a shared idea of the "silicon superorganic."

In any case, the term social media was coined by those who perceived what Berners-Lee had introduced to the internet with the social link, and affordance that followed from his grokking the social logic of the internet baked into it by packet switching,

In other words, early uses of the phrase in the context of internet communication were expressions of the cultural logic of the internet phrased as discoveries. The WWW was the original social media form (social medium) in that it was conceived as instrinsicly social.