The trio squad option originally left the game on Tuesday night when the patch for season three went live. It was replaced by the new quad squad option, which let players queue up for matches with squads of four. While many players seem to enjoy the quad option, there were still a few that missed the traditional trios that the game has had since launch.
To accommodate both types of players, Infinity Ward seems to have compromised and added trios back to the game, while still keeping the new quads mode available for the players that want it. With both options in the game and solos, Warzone now has three different battle royale queues available for players to choose from. That may mean that everyone can play the game the way they want to, but it also splits the population into different queues, but for now it doesn’t seem like matchmaking times are a problem.
Infinity Ward added the quads squad option to Warzone as part of the season 3 patch for the game, but it’s possible that it goes away after season 3 is over. It’s unclear if Infinity Ward will ever disable trio mode again, or if the developer turning it back on means that it’s going to be the game’s default mode from here on out.