It was JJ Anisiobi, on Talk TV on the day after Piers Morgan stated the names from the Dutch publication, who said that his source - someone who works with the Queen and who is friends with Charles - told him that the alleged person is neither Charles nor Catherine. He is absolutely not a fan of Catherine (he thinks she's awful), and he is a big supporter of MM. So he would have no reason to deflect from the accusation in Scobie's book.
JJ said that as soon as the Oprah interview had aired in the UK, the RF were upset and spent a couple of weeks trying to work out what H&M were referring to. They pinpointed who it could be. He thinks Scobie is lying about 2 names in order to move on a story that H&M had no interest in moving on in their own projects.
Tom Bower and Lady C both have good sources, and they have both said at various times that the person in question was Camilla and Anne respectively.
We don't have any idea if there was one, two, three or more people in H&M's grievance book. We know MM conflated matters of security and titles into a skin colour issue, and we don't know what else she has decided to conflate into a racism issue. We have no idea what is in those letters between Charles and MM.
This is the reason why the RF are better off sticking to their NCNE/RMV stance. Until the day that H&M actually state themselves what was said, by whom, to whom, when, why, context, witnesses and follow on treatment (because, imo, actions speak louder than words where throw away comments are concerned), then it remains a matter of no case to answer. And frankly, since these conversations were with Harry, then he's the one that needs to go on record, no more second hand interpretations from Meghan.