Suppressing "The default interactive shell is now zsh" message in macOS Catalina
I found the solution on reddit. The solution is also mentioned in the &quot;How to use a different shell without changing the default&quot; section of the Apple support article mentioned in the bash warning: https://support.apple.com/en-us/HT208050/.
Add:
export BASH_SILENCE_DEPRECATION_WARNING=1

to $HOME/.bash_profile, $HOME/.profile or $HOME/.bashrc and restart iTerm. After that, the warning message will be gone.