The only reason I think they might get the right answer after all is that there is going to be so much weird stuff preserved, even as a tiny fraction of the weird stuff that exists today. Our civilization is such that a single individual with enough money and a dream really can just do something, a sculpture or monument in metal or stone, that will last for millenia. That's before we consider the profusion of dead but obviously high-tech and resource-intensive artifacts we'll leave behind in their millions, cellphones, cars, even VCRs... A lone individual has, by the standards of any other age, quite a lot of power. That will show in the record.

I'm reminded of the old quote: "We considered ourselves to be a powerful culture." We're not entirely wrong.