Hi! Our existing Slack orb behaves a bit differently from this beta/upcoming v4 version. This beta is testing the new functionality and behaviour.
Adding the job explicitly, and defining the message or data you would like sent to your Slack channel(s), gives a lot more flexibility for when and how you would like to be notified.
Due to the nature of orbs being immutable, there will be no impact when this eventually rolls out unless you opt to import the newer version of the orb.