Although the Apple website has not been updated with any new info, Siri is proudly proclaiming that WWDC 2016 will indeed be held in San Francisco from June 13th to June 17th. Although Siri didn’t explicitly say, it is almost certain that WWDC will once again be held at Moscone West, simply because it’s the best choice of venue for an event like this in San Francisco.
So either someone on the Siri team got excited, or something happened to delay the official announcement. While those dates have been rumored for some time, for those trying to plan a trip to San Francisco, Apple’s last-minute announcement each year is a point of stress. Siri leaking it may be funny or cute, but I think the company would do better by its developers and community to announce the dates earlier than mid-April each year.