Yeah, I think it's saying that it relies on the ECU knowing what gear the bike is in via a stock gear position sensor, and reporting that info through the diagnostic connector that the device plugs into.
I've got a similar device for a bike that doesn't have ECU knowledge of the gear position. The diagnostic port on the bike only reports speed and RPM, so the device has to do some calculations to figure out what gear it is in. That takes about a second between gear shifts, so it's a noticeable delay. It also requires recalibration of the device if you make big changes to the sprockets.