https://www.gamespot.com/articles/call-of-duty-black-ops-4s-blackout-beta-update-inc/1100-6461690/

Call of Duty: Black Ops 4's private Blackout beta is underway on PS4. Now that the first day of the beta has concluded, developer Treyarch has revealed a list of changes it is making to the mode, and they include a higher player count, quicker item pickups, and other refinements. [Update: Treyarch has rolled out more Blackout tweaks, including the mode's first special event, Fast Collapse.]

In a post on Reddit, Treyarch announced that it has bumped up the Blackout beta's player count to 88. When the beta first began, it supported 80 players per match--20 fewer than PUBG and Fortnite. However, Treyarch said that Blackout's player count was subject to change based on the feedback it received from players, so the number may fluctuate yet again over the course of the next few days as the beta opens up to more platforms.