When an automation rule is deleted, it means that the rule is no longer active and will not run on any prospects. Therefore, prospects will no longer be able to match the rule (A). The rule will also be sent to the recycle bin in paused mode, where it can be restored or permanently deleted (B). However, deleting an automation rule does not undo the actions that have already been applied to the prospects who matched the rule before . Nor does it delete any prospects who matched the rule (D). References: Using Account Engagement Automation Rules vs. Salesforce Flows