In addition to the potential TPS issue, there is one more part that may cause a problem. A failed O2 sensor/sensors may also contribute to increased fuel consumption, as the fueling is based on feedback from the O2 sensor and adjusted accordingly. So... a faulty feedback may mean an incorrect (as in higher) fuel flow.
Before running of replacing components i humbly suggest that the bike is properly diagnosed and analyzed.
Proper TPS function my be checked by comparing the vacuum after the throttle valve on both sides. The TPS value may be read as a voltage, but a faulty feedback may be a potential issue.
If both sides operates with similar vacuum, the TPS is probably working as it should, and next focus should be on the O2 sensors.
A too rich mixture would be reflected by the color of the sparkplug.
Also, resetting the long term fuel trim and checking the lambda correction value in real time may give a clue to a faulty sensor.
Allow me to elaborate this point:
With a stock mufler and fresh air filter, the standard OEM mapping in the bike should be fairly close to what the engine needs for proper fueling. Thus, on a new engine, it should be running well even before the adaptive table (long term trim on the non BMW world)is built. Actually, you may even experience that the OEM mapping calls for a slightly too rich fueling in order to make sure the engine does not run too lean. Hence, with a reset adaptive table, the lambda correction with a healthy O2 sensor should be next to nothing, with a possibility for a negative adjustment.
On the other hand, if the O2 sensor reports a too lean feedback when the actual fueling is normal, the ECU will command an adjustment command to increase the fueling in order to reach the proper mixture, based on the feedback from O2 sensor.