I don't really have to have a hypothesis, it's not that uncommon a term. It's used for all sorts of things including a fairly generalized 'insatiable and demanding metaphorical monster'. If someone offhandedly mentions Icarus it seems reasonable to assume they're not really alluding to a review of the Hungarian brand of buses posted to alt.rec.bus in 1991.
Take a look at, say,
http://www.nybooks.com/search/?s=moloch&option_match=&year_a...
Lots and lots of Moloch. Your hypothesis is 'it's a reference to some logorrheic blogger'. Sure, it's possible you're right but it's one hell of a weirdly specific guess. It's not like the three people to ever mention Moloch were Milton, Ginsberg and internet-man-addicted-to-his-own-typing.
Do you have another hypothesis about what the term means in context? I note that "it's a reference to Paradise Lost" is not very descriptive: for example, if I talked about "Google's Frodo" you might ask what I mean by that, and "he's a character in Lord of the Rings" does not answer the question.