I hope they get in right this time.
Looking at the published syllabus it appears nothing has changed.
The RAF Navigators were employed back in the days of writing ATPL exams, because the Navigation group questions, pre CAA, were actually produced by the RAF College of Air Warfare, so that's where the expertise lay. These CAA Ground Examiners became redundant around 1999 as the JAA question bank emerged, but of course there were no PPL questions, as it had never been the JAAs intention to include the PPL!
PPL questions became a sideline of those ex ATPL instructors who primarily filtered the worst of the JAA questions. None held flight instructor ratings and none had ever taugh PPL theory.
The BMAA produced their own PPL questions which the CAA printed, SLMG questions originally came from the BGA, maybe there is a clue here!