This assumption the Sussexes had that they ought to have been allowed input into the letter (they call it clarification, what they wanted was for it to not come across as party A telling party B how to treat them without their say so or at least their spin) is entirely emblematic of Harry’s relationship with Meghan I think. They feel entitled to control, or rather not have anyone else control, how they use their status and titles.
So many instances of he, they and she saying and doing things suggestive of the basic premise that everyone is equal: referring to people by their relationship to them rather than by their titles; service is universal; he’s your brother you deal with him; collaborate with the Queen; making announcements without consulting with the firm (sometimes having to retract them); “blindsiding” people by doing things without prior notice; xyz is my birthright and nobody can take it away from me/my children; and so on and so forth. Of course we all want and should be able to live our lives with full agency and independence. But this isn’t how Harry was raised, and it isn’t the family or context he comes from - and it’s not consistent with having accepted titles and other perks of a hierarchical, unequal system. It’s an outsider’s view of how life is for normal people. Harry has adopted this outlook - for whatever reason, maybe because it was the first available alternative to being second best that anyone offered him - lock, stock and barrel. It’s informing every move he makes. He’s tearing himself apart trying to reconcile his past with his present. He’s thick as pig shit, this can only ever have come from someone telling him “well why not? Why do you have to do what they say? Who says that rule has to apply? It doesn’t work for us so why should we?” and goading/pushing him to do xyz perhaps even using tactics such as “to keep our family safe”, “he’s just a man, your brother from the same parents, who cares if he’s the future King, he’s not better than you”, “you know what they did to your mom, I’m not going to allow it to happen to me”, “she’s just my sister in law, she’s not special, I don’t care if I never see her again” etc. (Harry obviously too thick to see beyond this to the fact that Meghan has dropped EVERYBODY - friends, siblings, a parent, a husband, co workers - except her own mother by following this “me first” philosophy, and perhaps not her mother only because she too lives by the “me first” philosophy. Of course she’d be fine with Harry dropping his dad and brother if necessary just like she’s dropped hers. They’d both see it as being true to themselves (selfish, we’d call it).)
I think Harry needs Meghan more than we know. He needs her to tell him how to live. Between them, they’ll push this ‘philosophy’ to the brink, because they can’t/won’t accept that their most valuable asset is vulnerable to removal by Charles and William. They will have had the “what if they take our titles?” conversation many times, and you can just imagine what they’d say (they’ll look like fools for putting us on an equal footing to Andrew, we’ll just sell tell all books/tv shows as we’d have nothing else to lose so we’ll just lay it all out to anyone who will pay us what we need to live the rest of our and our children’s lives without them - we’d end up in the same place anyway, better even as we’d be secure without having to work for it and they’d have lost us anyway etc). They need lots and lots of money. They have loads already, but they need more to live the life they consider their due. They have no money coming in and enormous expenses, desperation will push them to ever more dramatic and drastic acts of their egos and emotions don’t do it first. Moving back to the UK has hastened everything and I think it’ll unravel in quite short order.