Well if you look at the entry on the Edge site you'll see he's talking about virtual reality, being an (the?) early VR pioneer. That's why it's called post-symbolic, because as deep as archetypes are it is still symbolic in nature.
What this doesn't address is what kind of consciousness is needed in order to effectively communicate in terms of these constructs. Obviously it would be rich in a sensory way, but as you point out the psychologically naive can be easily swayed by the underlying messages, which can take the form of propaganda. Our minds would also need to be able to generate forms that are detailed enough in order to make full use of this kind of technology, but on the other hand having the means to do so would enable us to practice and exercise that ability. He mentions the concept of homuncular flexibility which is interesting, where the brain can learn to remap control of different body forms.