ok, nothing was lowered, but nextgen and the reliance on satellite based navigation is allowing the planes to take more direct routes. this necessarily takes them over areas where they didn't fly before.
i'm sympathetic to the homeowners, but the routes are more efficient and planes burn less fuel. and if the difference is really only a few miles as the guy said in the video, we're talking about ~15 seconds of inconvenience per plane (planes look like they're flying over the lakes ~300 kts), and from checking adsexchange/flightradar, we're not talking about a huge number of planes.