I think the Oprah statements / confusion over titles for Harry’s kids was based around a speculative conversation that Charles had included Harry in and presumably William around the time Harry was getting married / expecting Archie.
Charles couldn’t do anything on his own re titles for Harry’s children until he actually became King and at that point no one knew how long that would be (or if ever).
It makes sense that for a slimmed down monarchy you start reducing the number of hereditary titles outside of the heir line.
But how and when to do it is complicated - before the offspring who would lose titles are born, or after retroactively like some of the Scandi Courts?
I don’t think Charles wants to do any title removals so once any kids are born they are treated under current rules.
What I hope he does do is create a new Letters Patent soon that would clear up any confusion for the children of Charlotte and Louis way before they are married and having kids - so that any change will be established and not seen as a reaction to who they have married.
What I don’t understand with Harry and Meghan is why they want to use titles now when they had decided against using the courtesy titles already available for Archie and Lili?
They should have been styled as Archie, Earl of Dumbarton and Lady Lilibet Mountbatten-Windsor as per regular styling of children of a Duke.