Re: Shouldn't the new names all start with a "W"?
There aren't enough words beginning with X, Y and Z. Unless we want to have HMS Xylophone...
We've also had a few smaller classes of nuke boats, the Chuchill class of 3 and the Valiant class of 2.
They might go for some of the "I" names, often used on carriers/battleships/battlecruisers. So names like Invincible, Indefatiguable - because you don't want to be calling a ballistic missile submare HMS Surprise. Or HMS Swindon either...