I'm not sure, but in section 4.1.2 of the PDF, it says:
Beautiful landscape will be displayed in the cabin
I took this to mean that there would be windows.I agree about not wanting to look outside, though. I've travelled on the shinkansen in Japan (which go ~ 1/3 of the speed that the hyperloop is planned at) and it was really hard to look out of the windows for any length of time.