Draft: Explore alternatives for including Release Supervisors in RM Slack events

This is a WIP

Problem Statement

We've recently onboarded contractors as Release Supervisors who need to be notified of critical release events alongside our Release Managers. However, we're facing Slack workspace constraints:

Cannot add contractors to existing @release-managers group - Due to company policy and workspace configuration
Cannot create a new Slack user group - Admin permissions required that we don't have access to change

This issue is there to discuss a visibility gap where Release Supervisors may miss Slack notifications targeted to @release-managers that require awareness or action, such as when packages are ready to be promoted or when a deploy fails.

Current State

Release Managers (@release-managers) are currently pinged for a variety of reasons including, but not limited to:

Package promotion readiness
Deploy failures
High severity incidents

Desired State

Release Supervisors receive are also notified on specific release-related events as Release Managers
Release Managers remain the primary group, especially for incident management
Solution should scale as we potentially add more Release Supervisors
Solution should be easily "revertable" for we find a more elegant solution using Slack's infrastructure.

Constraints

No ability to modify Slack workspace settings or user group permissions
Should not require significant changes to existing workflows

Questions to Explore

Can we use Slack workflows or automation to forward messages?
Are there bot/integration solutions that could bridge this gap?
Should we consider non-Slack alternatives for certain notifications (ie: email)?

Acceptance Criteria

Solution identified that ensures Release Supervisors receive critical notifications
Documentation for how to notify both groups
Solution can scale with additional Release Supervisors