One of the big topics surrounding Blackout is the player count that is available in the mode. The new Call of Duty: Black Ops 4 Battle Royale mode started off with a player count of 80 when the beta launched on PlayStation 4; the player count then rose to 88 across all three platforms, and the beta ended with 100 players.
Vahn said that testing 100 players taught them information on how to adjust and stabilize the game as the focus towards launch. One of the things Vahn mentioned is that they are not committing to a final player count for launch as they are still tweaking the numbers based on beta data and internal preferences.
One thing Vahn hinted at though is he wants the player count to reach 115 in the mode to support the Black Ops universe lore (115 is a number referenced in previous Black Ops games) and hopes that testing will enable it for special events in Blackout.
You can watch the GameInformer interview here.