I suspect it's just a cheap, 2-wire fan and the thermistor is used to reduce the voltage supplied to the fan "when cold" (conversely, to increase the voltage when HOT). It's a cheap little box. It's amazing that they could fit as much cruft into such a small space without resorting to, e.g., laptop components! Esp given its age!
(For example, i have some EzGo E7041's that have MORE I/O's in boxes
1/3 this size -- but, they rely heavily on laptop components for that level of miniaturization.)