Frequency is a function of Young's Modulus AND dimensions. A skinny tubed Vitus does absorb energy, losing especially higher frequency vibrations. A hyper rigid Cannondale does not. That's because the Cannondale uses its dimensions to exceed the rigidity of even a normal steel frame. The kind of vibration cyclists care about are solidly within the frequency range that a Cannondale is going to transmit like crazy.

Which is why it is important to understand the difference between the properties of a material and a structure. It keeps you from saying absurd stuff like carbon fiber composites are brittle or steel is the strongest metal.