Blizzard has posted the schedule they have planned for Blizzcon 2019, but is very vague at this point.
While former years the developer would post the names of the franchises they were discussing during their presentations, the placeholders now say coming soon.
For people attending Blizzcon, expect the main announcement to get further details after the main ceremony at the Mythic stage on November 1st. You can check out that schedule below, and see everything Blizzard has planned within this link.
Expect more information on Overwatch 2, Diablo 4 and a possible Diablo 2 Remaster, and more information on where World of Warcraft retail and Classic is headed.