Just a few days ago I posted a command to remove decoratives from concrete in already existing worlds.
But this won't ever be a vanilla "setting". Each tile type has a seperate deco-removal probability. And vanilla doesn't even have "Startup" type settings like mods do. It's also not good game-play to just make it a setting. Imho if it ever happens it will be a capsule or robot based solution, or a permanent change.