In the user opinions and reviews section at gsmarena, someone said that the B35 uses Kai OS. So probably the same OS for the B40.
Should be more private than a iOS or Android phone just for the fact that’s a “dumb” phone. No wireless no GPS. Basically just phone calls and SMS. I don’t know if there’s anything more privacy friendly than that out there.
gsmarena says that it doesn’t have GPS. The official site doesn’t mention it either.
The best part is “Operating system: Proprietary”. Strange that they don’t have a name for it…