From what I have always gathered, things such as clothes, lifestyle, homes etc are funded "privately" so for William and Kate and Harry and Meghan that was via an allowance from Charles from the Duchy of Cornwall. Everyone else (Anne, Edward, Sophie etc) received there's from the Duchy of Lancaster via the Queen.
Now Charles is in charge of the Duchy of Lancaster (I think that's it's name?) and William the Duchy of Cornwall. The latter was set up as a source of income to the heir and their family so even if Harry and Meghan were still working royals, they would now receive money via Charles and the Duchy of Lancaster and not via William and the Duchy of Cornwall.
My guess is that it's done on a financial year basis so really there's no change until April when William will take full control of the DofC. Will be interesting to see if we notice a significant ramp up in the Wales's spending now they will have significantly more funds at their disposal or if they will stick to the allowance amount they've received from Charles in the past.
It's all murky line because it's not taxpayer money, it is private income earned via the Duchy, but of course they wouldn't have access to it if they weren't who they are. I'd like to see more on the Duchy and what William does with it now he's "in charge" it has good potential.