Can't generalize of course, but in my company there is a "healthy" mix of both bullshit texts and useful texts. And I'm guessing that this is the case in other companies. E.g. we have technical writes who are responsible to writing proper documentation and they are not going anywhere (yet). There is a majority of internal communication and it is mostly technical and on point. And at the same time there are many bullshil letters send to the company. Almost all letters from the C-suit fall there, because they need to pad one sentence (John Doe is appointed as a Director of Directorship) to a full page of A4 text. Most of the letters from HR/LND unless they are about some factual info, like here is a new service and how to use it. Monthly/Quarterly updates are often padded so much that they are unreadable.

I'm guessing that most of the C-suit are already using NNs to write (and read) those kilometers of word salad.

A lot of copy doesn't need top writers. I think what we'll see is companies who adopt LLMs in tandem with their writers will get more productive than companies that go all one way or the other. And over time, there may be less writers required. I say 'may' here because humans have a knack for using any available capacity.