Yeah, the maximum cabin pressure differential will be maintained as the cabin altitude rises.
However, I got the following question in the exam so be sure not to mix the 2 up...
A pressurised aircraft is in cruise at FL330 with the cabin altitude at 8000ft. A climb is then made to FL350. Regarding the operation of the pressurisation system in an ISOBARIC mode:
Answer: The differential pressure will increase to maintain a constant cabin altitude.
Good luck with the exam..it's a fun one
