Yes, There Have Been Aliens
nytimes.com
nytimes.com
In other words, even if the paper's calculations are off by a factor of a billion, there must've been 1000 civilizations before us. And, no, that's not proof but more of a rethinking of a thought experiment based on new data.
If you wanted to dispute this, you'd have to show how any of the estimated numbers is wildly off or that the model (Drake's equation) is all wrong somehow.