Voilà :)
The default interactive shell is now zsh.
To update your account to use zsh, please run `chsh -s /bin/zsh`.
For more details, please visit https://support.apple.com/kb/HT208050.
Air-de-Carla-2:~ carlawillems$ diskutil eraseDisk jhfs+ CLE gpt disk4 ; diskutil list disk4
Started erase on...