One thing the article mentions is to alias rm, but they never mention just performing a chmod to change the user/group permissions on the actual command itself. I can't see why it's impossible to change the permissions on the real rm command, while providing an alternate (or aliased, whatever you prefer) command to move "deleted" files into the Trash/Recycle Bin/What have you.

You can later implement another in company program to perform the actual deletion, with strict warnings, which can execute the real rm command with the appropriate group permissions. Ideally, this should at least deter users from blanket deletion of their file systems, though eventually some will come to abuse the true deletion program, believing they know better than IT. However, this is largely inevitable, and some users will always behave that way, so you need to consider this when discussing any technical measures taken towards something like rm.