Meh, there's no proof, a whole lot of speculation, and bad speculation at that, IMO. This guy really thinks that Apple cares that there's "too much" to announce? Really?? This is a company that has got a lot of jollies from the "One More Thing" model of stacking up great news, and they're going to break up (read: dilute) that potential excitement by holding multiple events rather than have "A few more things!" ? ? ?
If October has an event and the rMBPs are ready to ship, they'll announce them. As many people have pointed out in this thread, they're not going to delay release of a sellable product for an extra month for no good reason.