I'm a republican who was waiting for Harry to reveal all about the royal family! Didn't happen. Just a risible, self-absorbed, embarrassingly uneducated pack of lies. I'm glad Moerhinger has admitted it was a less than optimal job, done for a million quid. (And yes, I'd do the job too for that money, probably.)
Harry has in the past six years stayed remarkably tight-tipped especially about the York ensemble - Andrew the alleged sex offender and betrayer of state secrets; Sarah and Eugenie the matchmakers and introducers of certain persons to other certain persons for fun relationships or maybe more; and Beatrice the 'private equity analyst' with interests that stretch all the way from daddy's Crown Estates to the Emirates.
The big questions for the whole royal family - notably those with titles - all coalesce around 'Who knew what about the Yorks, and when did they know it?'
The Secret Service Bureau (i.e. MI6) has a big old file on Peter Mandelson and his problemmatic connections with problemmatic Chinese, Russian and Israeli contacts. I'm pretty sure they hold similar files on family members of the Head of State, and brief the necessary people - who, being human, will tell the information to others who are close to them and/or those they believe should know.
(Btw I'll bet a lot of money that there are chunky files on all the Yorks, and Harry, and Meghan.)