Is it safe to use a propeller plane to fly commercially over the Tibetan Plateau?
The video starts with Mt Everest straight ahead while in a left turn. And based on the video description, the flight took off from Kathmandu. The Nepalese AIP depicts this Mountain Flight Route, shown in red below, and the turn we see is the video would be the turn going back to Kathmandu.


— https://e-aip.caanepal.gov.np

Note that the Tibetan Plateau is north of the Himalayan range. If something goes wrong, a safe altitude less than the Jetstream's 15,000 feet limitation is within reach to the south or on the way back to Kathmandu:


— skyvector.com