According to Apple back then, “iOS uses Location Services to help determine if an iPhone is in these prohibited locations in order to disable ultra wideband and comply with regulations. The management of ultra wideband compliance and its use of location data is done entirely on the device and Apple is not collecting user location data.”
That being said, the good news is that in the beta of iOS 13.3.1, it has been discovered that Apple will be adding in a toggle switch that will allow users to completely disable it. This was posted on Twitter by Brandon Butch where it seems that in the upcoming iOS update, users will be able to disable the ultra wideband chip.
That being said, turning off the chip could have some side-effects on the functionality of your device. There are rumors suggesting that Apple could be planning to debut a Tile-like tracking accessory that would leverage the U1 chip, so disabling it could also render the accessory useless.