Ideally they'd hold off until we were in a place where they thought we could handle it, but I can also see the argument made that the damage is just "growing pains" that every society in the universe has to eventually deal with, and that societies which survive the initial societal damage will recover quickly with the help of the knowledge and technology they gain access to while closed-minded and inflexible societies that fail to survive the initial societal damage might not be the kind of folks you'd want to be a part of your interstellar community anyway. How we'll react when confronted with the fact that we aren't alone in the universe might be the test that determines if we get to join to club, or be sold as pets, or put to work in the mines, or just get left alone.