Question about map's theme

How do they decide which and how many maps to make for OVerwatch, Apex, Fortine, CSGO, etc?

Mostly through market analysis. This is a business/creative director/executive producer level decision.

Say a game is aiming at WWII setting, how do you decide which cities or places to go? How is the creative process?

You general create pitches for a whole load of locations based on how they work for gameplay, general thematics/narrative themes, landmarks, etc and then pick from the best pitches to move forward with.

It really depends, what's the quality level? What's the team's experience level? What tools are they using? If they are using Duke 3D editor you could literally make a map per day, but if you are aiming for PS5 graphics you will need a big team and tons of time to make just one map...

Quote from Minos

1 hour ago, Minos said: It really depends, what's the quality level? What's the team's experience level? What tools are they using? If they are using Duke 3D editor you could literally make a map per day, but if you are aiming for PS5 graphics you will need a big team and tons of time to make just one map...

ah man when I saw you replied I hoped you were gonna share some Overwatch trade secrets

For the Battlefield series, pretty much anyone could create as many pitches for maps as they wanted during pre-prod, then the art leads would select the one to move on with. The pitches came with some constraints on that they had to fit with what factions you could play with and what fronts/biomes we launched with.

The number of maps was dependent on production length and staff available, but usually the same number for each release