The sources pointed out that a product will need to first pass the PVT stage before entering to mass production, and between the EVT and PVT stages, Apple could still be change its design. As for Apple's press conference on September 9, the sources said that Apple is unlikely to unveil the iWatch during the event. Currently, the upstream supply chain is mainly waiting for Apple to place component orders; however, Apple has not yet given a firm schedule for the production.
While other reports have said that the iWatch may not ship until next year, there have been numerous reports confirming it will be unveiled on September 9th. In addition, Apple's preparations for the event indicate something bigger than just a new iPhone.