chore(aci): Add feature flag for disabling issue stream detector notifications for metric issues

src/sentry/features/temporary.py

@@ -485,6 +485,8 @@ def register_temporary_features(manager: FeatureManager) -> None:
     manager.add("organizations:ingest-through-trusted-relays-only", OrganizationFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=True)
     # Enable metric issue UI for issue alerts
     manager.add("organizations:workflow-engine-metric-issue-ui", OrganizationFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=True)
+    # Disable issue stream detector notifications for metric issues
+    manager.add("organizations:workflow-engine-metric-issue-disable-issue-detector-notifications", OrganizationFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=False)
     # Enable new workflow_engine UI (see: alerts create issues)
     manager.add("organizations:workflow-engine-ui", OrganizationFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=True)
     # Disable redirects from alert rules to the new workflow_engine UI

src/sentry/workflow_engine/processors/detector.py

@@ -279,9 +279,21 @@ def _is_issue_stream_detector_enabled(event_data: WorkflowEventData) -> bool:
     if group_type_id not in disabled_type_ids:
         return True
 
-    return group_type_id == MetricIssue.type_id and features.has(
-        "organizations:workflow-engine-metric-issue-ui", event_data.event.project.organization
+    if group_type_id != MetricIssue.type_id:
+        return False
+
+    organization = event_data.event.project.organization
+
+    has_metric_issue_ui = features.has(
+        "organizations:workflow-engine-metric-issue-ui", organization
+    )
+    # For most users, the issue stream detector for metric issues will be rolled out along with the metric issue UI.
+    # For users who find that behavior undesirable, this feature flag will disable it for them.
+    disable_issue_stream_detector_for_metric_issues = features.has(
+        "organizations:workflow-engine-metric-issue-disable-issue-detector-notifications",
+        organization,
     )
+    return has_metric_issue_ui and not disable_issue_stream_detector_for_metric_issues
 
 
 def get_detectors_for_event_data(

tests/sentry/workflow_engine/processors/test_detector.py

@@ -922,6 +922,22 @@ def test_activity_update_with_feature_flag(self) -> None:
         assert result.preferred_detector == self.detector
         assert result.detectors == {self.issue_stream_detector, self.detector}
 
+    def test_metric_issue_with_disable_detector_flag(self) -> None:
+        """When the disable-detector flag is set, metric issues should not use the issue stream detector."""
+        self.group_event.occurrence = self.occurrence
+
+        event_data = WorkflowEventData(event=self.group_event, group=self.group)
+        with self.feature(
+            {
+                "organizations:workflow-engine-metric-issue-ui": True,
+                "organizations:workflow-engine-metric-issue-disable-issue-detector-notifications": True,
+            }
+        ):
+            result = get_detectors_for_event_data(event_data)
+        assert result is not None
+        assert result.preferred_detector == self.detector
+        assert result.detectors == {self.detector}
+
     def test_non_metric_issue_in_disable_list_with_feature_flag(self) -> None:
         """Feature flag override only applies to MetricIssue, not other disabled group types."""
         self.group.update(type=FeedbackGroup.type_id)