I dont know if that is correct.
However, I did see a comment that the Queen made Prince Philip the regent should it be needed for Charles. If true then I suppose William could do the same once he was King but not sure he could do it before he became King.
Once Ling Charles III dies...William becomes the King! That's it, no if, ands, nor buts!
Good grief...don 't any of these morons know ANYTHING AT ALL about UK history? Do they imagine that the period known as "REGENCY", vis-a-vis furniture, architecture, etc., was just some silly name and NOT because King George III was drastically ill ( some though mad, but he wasn't, he had a REAL illness! ) and so, his FIRST BORN SON became the Regent?