> generates a one-way hash code from the detected device’s MAC address (using a SHA-256 algorithm)

This does not sound truly "no way to reverse" if they are using plain or some simple variants of SHA-256. There are only up to 2^48 possible MAC addresses (way less in practice), which is a very realistic number for rainbow tables.

That said, this might be less relevant quickly as more and more devices are going to use randomized MAC addresses for probing Wi-Fi networks.