Even before the Pixel 4 was launched, Google made hype about Project Soli that uses a radar chip to detect actions and record gestures. Unfortunately, Google couldn’t manage to get approval in all the countries so the usage of Soli sensor is limited to only a handful of countries.
Since Google didn’t launch a Pixel 4 device without the Soli radar, the Indian government already stopped the launch of the device in India. The government stated national security as the reason and noted that the Indian army uses the same frequency so a private company can’t be allowed to use it. Now, it looks like the places you could actually use the soli radar is pretty limited. According to a support document, motion sensors are supported only in the US, Canada, Singapore, Australia, Taiwan, and most European countries. Google didn’t reveal which European countries will actually support the motion sensor but the list seems to be missing a whole chunk of the world.
That’s not even the worst part. According to the document, if you take the phone in an unapproved country, the motion sensor will stop working. This means if you buy the phone in the US and travel to China or India, you won’t be able to use any of the radar related features which might include face unlock as well.
Check that you’re in a country where Motion Sense is approved. Currently, Motion Sense will work in the US, Canada, Singapore, Australia, Taiwan, and most European countries. If you travel to a country where it’s not approved, it won’t work.
Since Google’s location services collect basic data even when you don’t have GPS on, the only hope you could have is to put the device into Airplane mode before going to an unapproved country. Even then we can’t be sure if Google will detect the change in location or not. For now, you might want to drop the idea of importing Pixel 4 from an approved country to try out the motion sensor.