If you are using 1000Base-T, you only care what the cable is doing up to 250MHz. If you are using 10GBase-T you care about performance up to 500MHz. Anything beyond those numbers is just more marketing hype. You've probably seen patch cables that say they are tested up to 350Mhz, or something similar. But what does that mean exactly? There is no network technology that operates at exactly 350MHz, and no standard to say what the performance characteristics are.

Can you say that the 6e cable is better than the Cat6 cable? Absolutely, it probably is better cable and probably does at least come close to being Cat6a. It just doesn't matter.