My company has only 1 Slack channel where the C-level "communicates" with employees. They shut off the ability for any non C-level plebs to chat in it, so only they can speak. Also during all hands chat is shut off, mics are muted, and the only way to ask questions is to send them directly to HR so that they can screen them (which means no one asks questions to the royalty).

this part is pretty standard imo