The O2 sensor wiring recall jives with what I saw when I looked at my O2 sensor connector a week ago.
The connector is behind the radiator side cover so it's not directly exposed to splash, and the connectors have seals on both sides. But, due to the way the wiring is routed, I noticed that one of the wires on the top connector exited the seal at an angle, 'opening' up that seal slightly. Water could potentially leak down the wiring and into the compromised seal and over time can corrode the connection.
I don't ride in the rain and I don't wash my bike so there was no corrosion. I'd imagine someone who dailies their bike rain or shine, or washes their bike often, could have a problem with that.