Ultimately it won't have to be explained since equipment will just negotiate, but the flip side is that virtually no one will be using 6 GHz for the next ten years or so.
If there are two boxes on the shelf, one with "Wifi 6" written on it and the other "Wifi 6E", it will be someones personal hell to explain the difference between the two to a customer who is not technically minded enough to understand "6E is faster, but only if your other devices are also 6E", but is completely obsessed with making the absolute optimal decision about whether the extra $20 is worth it.