Va is only to ensure that control surfaces don't get damaged. In the regulations the minimum Va speed is sqrt(n)(Vs) but that is only the minimum, and hence why you see the FAA circular saying that Va doesn't guarantee you won't break the airplane!
Read FAR 23.335(c), 23.423, and 23.441.
The first sentence in 23.423 says:
"Each horizontal surface and its supporting structure, and the main wing of a canard or tandem wing configuration, if that surface has pitch control, must be designed for the maneuvering loads imposed by the following conditions"
This is specifically for the control surfaces and supporting structure.
What you're thinking of is actually called Vo - maximum operating maneuvering speed. Reference FAR 23.1507.