Note that this is only applicable to binaries with an SMA of a thousand AU or more, like 55 Cancri. At alpha-centauri-like separations, I'd imagine the stars have such a strong gravitational grip on each other that perturbations didn't change the eccentricity much.
Also note that planets in the habitable zone wouldn't be disrupted - at least not directly. However, objects scattered inward by the companion star could collide with inner planets, or if said object were large enough, become a gravitational threat themselves.