Undone the deleted comment with a little modification

moveit_ros/planning_interface/move_group_interface/src/move_group_interface.cpp

@@ -112,6 +112,8 @@ class MoveGroupInterface::MoveGroupInterfaceImpl
                          const std::shared_ptr<tf2_ros::Buffer>& tf_buffer, const rclcpp::Duration& wait_for_servers)
     : opt_(opt), node_(node), logger_(moveit::getLogger("moveit.ros.move_group_interface")), tf_buffer_(tf_buffer)
   {
+    // We have no control on how the passed node is getting executed. To make sure MGI is functional, we're creating
+    // our own callback group which is managed in a separate executor
     callback_group_ = node_->create_callback_group(rclcpp::CallbackGroupType::MutuallyExclusive,
                                                    false /* don't spin with node executor */);
     callback_executor_.add_callback_group(callback_group_, node_->get_node_base_interface());