Nope. A user switching to zsh won't effect how scripts are run (which is why your scripts should begin by saying what they're using /bin/bash, /bin/sh, etc).
And, for now, bash, python, and the other languages being discontinued will continue to work... but they could go away in the future (probably with 10.16, but it could be 10.15.3 or something). So, take the time now to review all your shell scripts, and the scripts you may have in pkg installers.
And with Catalina the path to some things has changed. So, test all your scripts.
jamf binary executes scripts as files, so whatever shebang you are using in code it will execute as. Also, technically
bash is not going away, it is just no longer the default shell. There is also nothing stopping anyone from shipping their own
bash version 5 binary either. There are still plenty of options to look at.
If there is any glaring lessons to be learned here, is that as an I.T. Admin/Engineer you should really use VCS systems and centralize your code in a repo, so in the event you need to convert or rewrite, it is a lot more easy than chasing downs tons of scripts. Also, try to write reusable static code, it makes things a lot easier.
I'm a bit late to the game, but I haven't had time to check this until now.
I want to check if some of my current important scripts in Jamf (in bash) would still work should Apple decide to remove bash in coming versions. Sadly, ShellCheck doesn't support zsh. Is there another easy way to check if the script contains errors for zsh? Or is zsh --emulate sh an option for this?
I'm still quite new to Apple and Jamf, so I'm trying to figure everything out as I go.