Likewise, zsh will look for /etc/zshrc
And zsh will actually look at
$ZDOTDIR/.zshenv $ZDOTDIR/.zprofile $ZDOTDIR/.zshrc $ZDOTDIR/.zlogin $ZDOTDIR/.zlogout
https://eng.libretexts.org/Bookshelves/Computer_Science/Oper...
https://bash.cyberciti.biz/guide/Setting_system_wide_shell_o...
https://zsh.sourceforge.io/Intro/intro_3.html