Maybe Satoshi created this "puzzle", and once all the private keys are found... maybe a hash of the string composed of all the keys within individual ranges, or maybe something related to them... could lead to the private key that "controls" the addresses that received the first mined bitcoins. Science fiction ? XD
I can't see any science in your theory, it's just a made up scenario in your head, I doubt him to be a liar, he said that he used a deterministic wallet to generate the keys.
The only thing I don't understand, are all the keys from one seed and if they are, did he use the first 256 keys and didn't generate more? If he used the first generated 256 keys, which would be impossible to generate 256 keys and all of them have the exact bit range of the intended bit range.
So my guess is that he might have used a single seed but had to generate more than 256 keys to find the perfect keys matching the intended bit ranges if masked with leading zeros.
So explain what I mean.
Imagine I generate 256 keys and see none of them has 1 in the middle so that I could mask anything behind 1 with zeros and use that key for puzzle #125, for instance.
Example
5efad5987dc4a907698547d117b98892 0 5001159481c639e043e52d4f9b832e1
I can't use the key above for puzzle #125 because it has 0 in the middle instead of 1, so I'd either have to manually replace 0 with 1 or generate another key till I see 1 in the middle.
In both cases there will be no pattern, no correlation between the keys whatsoever.