I have a friend who works for an insurance firm. This company enforces HIPPA requirements of not saving any personally identifiable information by prohibiting any means of saving information. They aren't allowed their phones, nor paper, and the computers they use are basically kiosks without access to text editors. That made for difficulties in staving boredom and in helping people across different days (given they'd need to remember the context). That's an extreme example, but not impossible if the requirement is to be able to reproduce all communications relating to some investment instrument.

I don't doubt that some high value employees probably already have company phones. For the others, I wonder if they will have to surrender their phones to not use them during the day or to have the chat history, forfend, exported.