Update: It turns out that my guess was a little off the mark: The Black Ops 4 Blackout beta will come to PC on September 14 for those who have preordered the game, just four days after the PS4 beta begins, and September 15 for everyone else.
Mark your calendars: The Blackout PC beta goes live September 14th at 10am PT for those that have pre-purchased any digital version of the game. The Blackout PC Open Beta is available to anyone with a https://t.co/d5IQWYDE9D account starting 10am PT on September 15th pic.twitter.com/ElRScDOGJiAugust 20, 2018
Activision announced today that the second Call of Duty: Black Ops 4 public beta test will begin on September 10. On the PlayStation 4, that is—the rest of us will have to wait a little longer.
Prepare accordingly.#Blackout pic.twitter.com/X70KVQ75gUAugust 14, 2018
Assuming the schedule follows the same pattern as the first public beta, which debuted on August 3 for PS4 and August 10 for PC and Xbox One, we can expect it to come to PC the following weekend—so, September 17. An Activision rep said that date hasn't been confirmed yet, but I'll update if and when it is.
The first Black Ops 4 public beta featured six conventional multiplayer modes and introduced a few major changes to the series, most notably the end of auto-regenerating health. Round two, as the tweet makes clear, will be all about Blackout, the new battle royale mode that was announced in May and teased, very briefly, at the end of July.