Blizzard revealed the schedule for BlizzCon 2019, complete with sections for various games and esports, as well as a panel with voice actors, which is something the company skimmed on with the cancelled Overwatch launch event for Switch.
Good news for Blizzard is that the esports part of BlizzCon 2019 will mostly go on at times when League of Legends World Championship 2019 is not broadcasting but it's also bad news for all the other BlizzCon streams.
For example, all three esports events will start off on Friday, 1 November 2019, at 8:15 CET/ 12:15 PM PT. Hearthstone's schedule hurt itself in confusion though, so those watching the tournament will miss out on the Hearthstone Update that will go on from 5:15 PM PT/ 1:15 AM CET (2 November) to 6:00 PM PT/ 2:00 AM CET.
Voices of Overwatch will happen at 5:15 PM PT on 2 November 2019 / 1:15 AM CET on 3 November 2019. Fans who wished to meet the amazing voice actors from the hero shooter at Switch launch event were undeniably disappointed to see the event cancelled but at least some may still get the chance at BlizzCon 2019.
The schedule doesn't say anything about announcements for Diablo 4 or Overwatch 2 at the moment but none of the Mythic Stage events on 1 November 2019 are unveiled yet. Therefore, this is where you should keep your eyes peeled for reveals of the two games and potentially first official details about them.
Technically, League of Legends' tournaments shouldn't interfere with BlizzCon stream popularity due to different audiences but Blizzard are definitely not going to like the biggest esports event in the history of gaming happening at the same time.
You can check out the full schedule on the official website.