I haven't personally noticed that, but I attempted a VPN comparison like you did. On one hand, it would would make it harder for neighbors, regulators, and law enforcement to take action against Airbnb hosts, but on the other it would also make it more difficult for guests to hop rentals when they are visiting a city and choose to extend their stay.

Of course, Airbnb has been accused of manipulating data before, when it was noticed that they removed a large number of listings just before handing a dump to the NY attorney general, so I wouldn't put it past them by any means.