That 96 LP is interesting to read in light of changes to the Succession Laws. It's written about ex wives, not ex husbands and now that a Princess of Wales is possible in the future, it's discriminatory. It was published in August 1996 - if anyone wants to look it up and read it.
Not that I am hoping for any future divorces. I like steady/stable in my royal couples.
A female heir apparent was always possible, just unlikely - when Mary II died, the future Queen Anne was William III's heir apparent as the rules of succession had dictated that if any children of William's with a wife other than Mary would come in the succession after Anne.
The title of Prince/Princess of Wales is a tricky one in that the rules for the Prince of Wales state that the heir apparent is eligible to be Prince of Wales, regardless of gender, while the Princess of Wales is the wife of the Prince of Wales.
Now, if in the future there was a female heir apparent they might chose to make her Princess of Wales and amend the way the title seems to work now (now it could operate like the Duke of Lancaster or Lord of Man). However, even if they did that the wife of this hypothetical Princess would not be Prince of Wales or automatically an HRH.
Husbands do not take their wives titles. A woman might become Mrs. John Smith, but her husband doesn't become Mr. Jane Doe.
Part of this reasoning within Royal circles is that a Queen may be in her own right, or as Consort, but a King always holds power and in British history, the men who have held titles through their wives have held the power and authority that comes with it.
As such, while Charles' wives have both held his titles, neither of Anne's children have gained titles from her, and the DoE had to have LPs to create him a British Prince.
If there ever is a Princess of Wales in her own right then her husband will likely have LPs issued to make him a Prince of the United Kingdom and possibly a Duke - comparable to the DoE or Daniel of Sweden. But to have him be PoW would be incorrect.
I wonder if changes will be made in the future regarding the York title. At some point in the future, Charlotte will be in a position where that title should be hers in her own right. It will not really apply to Harry because once Charles becomes king, Harry will no longer be the spare.
There are no official rules about the Duke of York title, it's just unofficially that it's created for the second son of the monarch. Titles also tend not to be recreated while someone is still able to be "of" that place.
The next second son of the monarch will be Harry, however it's unlikely that he will be created Duke of York as he'll probably receive his Dukedom while Andrew is still alive, and even if he doesn't Beatrice and Eugenie will still likely be alive and be able to be "of York".
Charlotte is not the son of the monarch, second or otherwise, and will likely be created Princess Royal in time, but if they did want to give her a peerage (unlikely - whenever peerages have been created on the marriage of Royal women before, it's been for their husbands, not themselves), she likely still wouldn't get the Duke of York title as Beatrice and Eugenie may still very well be alive then, and still "of York."
The Duke of York title, while often not descending to the next generation, doesn't typically get use every generation. We forget this because it got used more in the last 100 years than previously - but that's because 2 of the last 3 Dukes of York have become King.