Vehicle regs require passenger restraints for safety reasons. That's only analogous to a very specific kind of hotel room. The bus exemption kicks in for vehicles designed to carry more than 10 people.

Also, hotel rooms tend to offer privacy. If you do that in a vehicle people get motion sickness.

To be clear, I do think there's interesting stuff in this general area. I'm just not sure it's as a sleeper bus. The big OEMs have loads of interesting concept designs buried in their basements about similar vehicles that I wish could see the light of day.