The thing that makes it not racist for me is that he's clearly trying to point out that, as primates, in non-Western surroundings and when not socialized to prefer soft beds with fluffy pillows we tend to adopt similar sleeping positions as other primates do. It would be very racist if he had adopted a sneering "look at the lowly primitives" tone, but he's trying to show that these sleeping positions have helped him immensely and he's suggesting that we might research sleep positioning more as there seem to be differences in the two populations under comparison.

You can look at the COVID pandemic for an example of how body positioning has helped change how well people can breathe. Proning of severely sick patients substantially improved outcomes. That's literally just rolling the patient from their back to their stomach. So there might be something interesting there that we can learn if we pay attention. And he's trying to say "we can learn something from these people if only we pay attention."

He's viewing humans and gorillas as primates, not viewing tribespeople as gorillas.

Tribes people don't live instinctually. They have culture, like us. The critique here is our culture could benefit from observing how their culture does it.