Re: the royal foundation split.
It's obviously been known for some time that Charles will one day be King.
However, it's only in the last year or so that his charities have become aware that they need to reorganise and change things, as he can't continue heading them all up in the same way once he's king (can't remember all the why and wherefores, but it involved some constitutional stuff).
Given that, I wouldn't be at all surprised if things weren't properly thought through when they set up W&H's foundation.
It may even be all the work going on behind the scene at the prince's charities that have prompted them to think "hang on, we'll have the same difficulties when William becomes King, so let's just sort it all out now and split W&H's charitable causes before they become too firmly enmeshed together and it's even more complicated to sort out further down the line".
I really can't read anything into the royal foundation split other than it just making sense from a practical point of view.