Warzone players, by and large, aren't fans of the Skill Based Matchmaking (SBMM for short) that's been thrust upon them by Activision. This method of grouping players together for multiplayer matches is hated so much that third-party apps were developed to help you analyze the stats of the players in your lobby. On January 14, however, it was discovered that Activision had chosen to hide your stats by default, breaking those third-party apps.
Before this change in privacy settings, an app had been developed and released that allowed you to see if you were in a lobby with cheaters. The idea was that, if a player had too high of a K/D spread, you could choose to leave that game and find a lobby with players with lower stats. Of course, this was soon taken advantage of, with some people going as far as reporting potentially legitimate players as cheaters—simply because their stats were too good.
The app maker changed the way that the app works so that you can't simply lobby skip until you find one with new players to stomp on. However, it didn't change the reporting feature that was associated with it. According to @CODTracker, Activision has decided to make your stats private by default, breaking the apps that relied on stats being public information.
If you want your stats to be public, you can change these settings by logging into the Call of Duty website, going to account preferences, then head to account linking. From there, you'll want to make sure that you set your "Searchable" and "Data Visible" settings to "all." If you don't do this, you won't be able to track your stats through third-party apps.
With this "opt-in" change, third party apps like the one that allowed you to report players based on their stats may have a hard time keeping up. The method for changing this setting isn't as easy as it could be, which means that the number of players to change their settings back could be limited. If the rumors are true, Activision may soon introduce a ranked playlist, which may be a good compromise for those who want to compete and those who are looking for a good time (or good content).