Ah to clarify: VanMoof make (very expensive) e-bikes with integrated GPS that's used mostly for "smart bike" features. I doubt the researchers could afford a used VanMoof for their study, and the company only tracks their own bikes.

I'd guess part of their motivation is to dissuade theft and resale of their bikes, which are quite distinctive. Though that might be attributing too much rationality to a bike thief.