It can in deed be removed. The link to the Navi is just a communication from Telematics to Audio over the Media CAN and MOST networks. Removing the Telematics unit alone wouldn't create any problems in the vehicle except CAN codes in the various modules, but not severe enough to turn on any warning indicators as the CAN communication will still exist since the TMU is not a gateway.
Good luck with whatever you choose, beware if you have any electrical issues with your vehicle as it will be at the dealer, DPSM and HMA to determine if they'll continue to warranty the vehicle. Removing major modules tied to various other modules is something they will not like.