That really holds only for legally acquired review copies - I don't think anyone contest the legality/morality of any reviews originating from those.

Discussing the content of leaked copies/illegally obtained copies is at the very least a very good way to get on the publisher's bad side and the publishers would be perfectly in their legal rights to take measures to have these reviews/spoilers removed from sites hosting them. I know it's the case for movie spoilers - I've signed enough NDA in two decades for the stuff I work on to know this - and I don't see why it wouldn't be the same for books that are protected by the same laws.

It's known Tor has not printed ARC for TGS and reviewers who've inquired are told copies of the book for reviewers won't be sent before late in the game, perhaps even on release date (Ken, Larry etc. all got that answer from Tor) You're saying Orbit too will send copies to blogger like you only late, shortly before the street date. From where exactly legal copies for review are supposed to come from until then? The few possible reviews from well-known players in the WOT community aside, the rest will be hoaxes and copies obtained through variously illegal means.