add comments about pending upstream discussions

internal/controllers/gateway/route_utils.go

@@ -86,6 +86,9 @@ const (
 	RouteReasonNoMatchingParent gatewayv1beta1.RouteConditionReason = "NoMatchingParent"
 	// This reason is used with the "Accepted" condition when no hostnames in listeners
 	// could match hostname in the spec of route.
+	// NOTE: This is not in upstream and still under discussion:
+	// https://github.com/kubernetes-sigs/gateway-api/issues/1561
+	// may be changed if upstream decide to use a different reason for this case.
 	RouteReasonNoMatchingListenerHostname gatewayv1beta1.RouteConditionReason = "NoMatchingListenerHostname"
 )
 
@@ -520,7 +523,9 @@ func getUnionOfGatewayHostnames(gateways []supportedGatewayWithCondition) ([]gat
 			}
 		} else {
 			for _, listener := range gateway.gateway.Spec.Listeners {
-				// REVIEW: which listeners should we take into consideration here if no listener in supported gateways?
+				// here we consider ALL listeners that are able to configure a hostname if no listener attached.
+				// may be changed if there is a conclusion on the upstream discussion about it:
+				// https://github.com/kubernetes-sigs/gateway-api/discussions/1563
 				if isListenerHostnameEffective(listener) {
 					if listener.Hostname == nil {
 						return nil, true