IMO, as an idea, this isn't post-anything. It fits very nicely (almost to the point of cliche) into the "modernist" family of ideas. Socialism was the most prominent political and economic philosophy of modernism. Objectivism is another example. Anti-socialists of the modernist period (who often objected to modernism as a whole) kind of parodied modernism in a way that is similar to this. Super efficient computers that calculate truth and can run everything optimally.
Fredrick Hayek (an early postmodernist) parodied social "scientism" and socialism in just this way. He argued that this kind of planning is doomed no matter how big your computer is because the requisite information is unknowable, not just unknown.
I see this as something like a 1950s science fiction work. But I'm biased. I don't think this will ever work and I hope it won't either.
If the information is unknowable, then it cannot play any role economically. If it is unknowable, the market itself cannot act upon it either. The idea lurking here is of inarticulable knowledge or inexpressible information -- and it is a contradiction in terms.
Hayek's big point -- in 'The Use of Knowledge in Society' -- is really this: an economic system is a cooperative system, a cooperative system requires networking/sharing information, and money and markets are a way to convey and share information.
Hayek does not prove that centralisation is impossible, nor does he prove that money and markets are the only means to run an economy. An argument based on information is not going to get you there -- rather the opposite in fact.
Later in that article, Hayek says -- about gathering dispersed knowledge etc. -- (not) "likely" rather than "never", and also says "it is just conceptually possible". That is the sensible view: if the market is performing a computation, then any sufficiently powerful general computer could emulate it and any sufficiently good network could transmit the relevant information around. Indeed, with enough power you could process more information than the money-market system.
And that is actually where we are now. When there is a pocketable networked computer for every human on the planet, that rather blows away the idea that we need money to solve the 'economic calculation' problem. The money-market system is already obsolete, it will just take some time to evolve away from it.
Also, for anybody interested in the general ideas check out the novel 'Red Plenty' by Francis Spufford. Its about attempts at a similar scheme in the USSR and the problems it faced (more ideological and organisational than technological)
What makes Cybersyn interesting for me, particularly in relation to the Soviet schemes, was the decentralised nature of it, including the (unfulfilled) ideas of bringing workers into the fold.
Also, the Adam Curtis series 'Pandoras box' (youtubeable I think) discusses both cybersyn specifically and the ideas around it.
Allendes Chile was actually relatively moderate in its socialism, in the sense that he was a radical reformist rather than a revolutionary.
I agree, however, that there was a great potential for something much more dramatic (ie, a true decentralised communist planning) within the cybersyn project.