Feature Request : Head banner visible on all channels, used by Admins as an emergency channels (e.g. ongoing P0)

It doesn't seem possible to do so as an Admin @Host Ever​ or it's because we're on Pro plan and not on Business/Entreprise Grid.

But are we 100% sure we can customize banners? From this help article, I'm unsure if it's just for telling Guests/Users who can see their messages, or if we can leverage it as we want

Similar question asked here: https://forums.slackcommunity.com/s/question/0D5PU00000hNh8d0AC/can-a-message-banner-be-implemented-on-channels?language=en_US