Burning man has extensive planning and infrastructure, which has been built up over years of adapting to slow growth, and which goes on for months before the event opens.

At burning man, people buy tickets months ahead of time, whose supply is limited, so the number of people in attendance is known. Road markings are put up on the playa to manage the huge volume of traffic entering the city (waiting in the gate line in your vehicle can take multiple hours, sometimes the better part of a day– remember, this is with good organization). Space on the playa for each camp is planned and allotted, and someone shows you to your space. Water trucks continuously spray the streets to keep the dust down.

Burners know what they are responsible for. There is basically not a single piece of litter in the city, because there is a strong and highly unified culture of not-littering and being responsible for your own garbage. Similarly, burners are fully self-reliant for water because there is unified understanding that there is little safety net if you screw up and don't bring enough.

This is a big one: At burning man, thousands of porta-potties are put up and routinely cleaned and pumped multiple times a day. The number of needed toilets is known because of ticket sales, and the ticket sales also pay for the toilets and their servicing.

None of this is true of the coming event, however big or small it is. Experience at burning man makes me more worried about how bad this could be without planning, organization, and a unified culture that strongly emphasizes self-reliance and respect.

Black Rock and Area 51 are not comparable environments, Black Rock is much more forgiving for the unprepared traveller. I've gone off-roading in both regions extensively. Black Rock is a relatively temperate and populated area for Nevada, albeit rural, and Pershing County has decades of experience dealing with thousands of unprepared people. The region around Area 51 is essentially a bone-dry wasteland with a couple mining camps in the area and nothing else.

The carrying capacity for excess population around Area 51 is all but non-existent, and far smaller than in the region around Black Rock.

I don't know first hand, but since it has been consistently tens of thousands of people, it's become really organized, according to what I read. The logistics aren't trivial or spontaneous. The people coming have some idea of how it works, not to mention many of them have a lot of resources.

But burning man provides the infrastructure. This like burning man but with no food, water, gas, place to stay, and folks possibly shooting at you...not exactly a direct comparison.