Sure, but that's not related to this study. Maybe that's something we'll detect over the course of hundreds of years of observing, but the shear scale of the t

Sure, but that's not related to this study. Maybe that's something we'll detect over the course of hundreds of years of observing, but the shear scale of the time of the universe makes the chances that some other alien species just happens to be going through an industrial revolution while we're around to observe it, are so astronomically small as to barely be worth considering. In your example, an intelligent species in an industrial revolution would probably be at the bottom of the list of likely explanations, simply because of how statistically unlikely it appears to be.