No one is going to churn Slack for this just because it is "Agent First". Slack is more than good enough to tag Agents and will fill in the missing pieces slowly
Slack's approach is NOT good enough, because the version of the Agent that lives in Slack cannot see the context of the Agent that lives inside Cursor on my developer laptop. They might be clones with identical brains, but they can't talk to each other or compare notes.
I would pay money to not have to use slack