Docs. Load-bearing implicit authority. Attribution of sales. Implicit assumptions about humor / topicality in group chats. Office kitchen standards & practices.

It’s up to the CEO to fix all of it, directly or indirectly. Except perhaps the chat one. You need someone with community-manager DNA and a light touch, lest the CEO come off as control freak. (Which is ironic bc they have to be one in many areas but this is one where it will alienate people)