The currently used Slack integration by Notifications is deprecated.

In order to switch to the new slack integration, users will have to do some manual action on Slack admin console.

From HCC side, to complie to the new way to integrate Slack, the "Channel" field have to be removed, because it's no longer supported.

On edit flow, the Channel field could be marked as read only for existing integrations?

FYI: Notifications backend has already been updated to support Slack integrations without the "channel" field ( RHCLOUD-24628 ).