"ban personal messaging apps at work"
What does that even mean? I doubt you can forbid the usage of personal messaging apps except in very exceptional cases (like a court room).
On the other hand: Using personal messaging apps for work related information is a no-go anyway because of confidentiality agreements basically everyone signs.
Using personal messaging apps for work, for example, sending work related messages through WhatsApp or Telegram instead of using the proper corporate/official app.
You can forbid your employees to use non official apps to send work related messages for privacy, compliance, security and other reasons.
Finance - no personal devices in the office and no personal (or unauthorised) messaging apps on your work devices.
I also didn't fully understand if the context is:
- Ban ANY use of your personal chats / device at work (eg. your wife texts you to bring milk on the way home)
- Ban WORK communication (eg. My colleague don't understand recent commit I've made)
So the web really isn't explaining how things enforced or what is being done. I do know of some industries where you put your personal phone when entering specific locations or having stickers on cameras) but here I didn't fully understood the scope.