Imho, but when you're reading some review that is not paid or paid but still reveals some cons you might be disappointed by this things or even become upset resulting in to:
1. changing your mind and not purchasing it ( saying you're most likely not going to buy it, although purchasing later)
2. sharing your 'negative' feedback to others before the article even goes live for pre-order
all this based on a 'prototype'; the moment when small cons might affect a pre-order hype that is really needed in order VR to success. We all need to understand that we should be interested not only in product itself but also in manufacturers wealthy as well.
Sharing a review within kickstarter campaign or afterwards might decrease negative impact of cons, mostly because people will be more impatient and might close their eyes on some cons, especially when we talk about time&amount limited packages as "early bird". So even if they pre-order and discuss things later - they are still customers who purchased the item, its a big difference when someone says 'i know there are issues, but i still purchased it' vs 'i know there are issues, therefore probably not going to purchase it' (even if he purchase it later, first opinion is very important too).
I think this could be an explanation - there are some cons that they wont reveal too early, because people like focusing on negative things. It's mot really 'hiding' information (like some people from this thread already called, a good example of feedback type that no one needs), its just finding the best possible time to share this info and maybe get more time to prepair/montage a better review.
p.s. the other side, since Norman isnt really going to test it, his "impression" from the demo might work as a good advertisement with no found cons, so maybe they want to launch it closer to kickstarter campaign