Every situation is so different with how the developers handle it, but not all the time. In some cases, the sequel ends up being just a fresh expansion for what was previously made, but not all the time.
What are the differences between Call of Duty: Warzone 2.0 and the first Warzone?
The first thing that strikes us when looking at the differences between the two Call of Duty: Warzone games is that Warzone 2.0 is its own game running on a separate client. While the game does still include integration with Modern Warfare 2 and future Call of Duty releases, it does not require the game to run it unlike Warzone 1, which must run through the 2019 Modern Warfare.
Another noticeable difference is the new map, Al Mazrah. Of course, you can expect new locations, but Warzone 2.0 will feature AI faction enemies that will populate the new map, similar to Fortnite's various AI enemies that appear near the playable area and attack you.
As the battle royale progresses, the circle will now be divided into three different circles to fracture the lobby into groups against each other. When those groups continue to shrink, they will reconvene into one circle for the final push.
The Gulag has also received some updates. Before, you were thrust into a 1v1 match to die for your life. Now, you will be forced to cooperate with an enemy player in a 2v2 quick match to return to the game.
These are the most important changes that we know about Call of Duty: Warzone 2.0. Also anticipate new cosmetics and events since your unlocks and progress from the first game do not carry over.