This rumor comes from DigiTimes who claims that Apple has started to procure the various chips and components necessary to create the Apple Watch 2. Shipments of these components have been rumored for the third quarter this year, meaning that production and assembling will take place around that time as well, which we can only imagine will result in a Q4 launch.
The report adds that Apple has been pretty aggressive with its orders for the second-gen Apple Watch. This is despite the fact that the first-gen Apple Watch did not sell as well as many had hoped, although if the statistics are to be believed, Apple is still leading the way as far as smartwatches are concerned.
In any case Apple has two more events for later this year, at least based on the previous years. One will be for their next-gen iPhones which should take place in September, and the other will see Apple refresh their iPads and if the rumors are to be believed, a new MacBook Pro as well.