If you ever notice, if you get a request that is about 20 minutes away it's usually a scheduled pickup.
I found out about scheduled rides when I was called away from my normal fishing hole for a 20 minute away ping. Normally I wouldn't but it was surging in that area so I went. It turned out to be an airport run (good for me). On the way there I asked if they had trouble getting an Uber because of how long they had to wait for me. They told me they scheduled the pickup. After that, I started polling every rider that had a long wait for pickup. Most of them turned out to be scheduled.The thing about that scheduled ride is, I am sure the closest Black car would be minimum 30 minutes away in that area. It didn't make sense to me. I wonder if Uber is contacting some drivers and forwarding them the information.