at least, not the ones I worked on (the girth measurement sees to that) . . . but they do have volume down low that rotates to windward when the boat heels and counters, to some extent, the volume immersed to leeward.
I remember doing a calculation on a fin-keel boat with encapsulated ballast. The extra volume needed down there for the encapsulation had quite an impact on the heeled CB -- really opened my eyes. But you look at photos of these modern production boats -- all beam and flat bottoms -- and they still heel pretty wicked in the puffs. And they certainly don't have the inverted instability of a 12-Meter!