It would be a great boon to BitCoin to know the identity of the creators.
Particularly if the unmasked progenitor(s) proved that they had actually destroyed the early Coins, that would help stabilize and legitimize the currency.
If Satoshi holds ~1M BTC it means he can crash the market at any time. In some people's minds that risk reduces the value of Bitcoin. But if he could prove that he doesn't, that risk goes away. Also, if Satoshi could prove he's not rich then people will stop trying to kidnap him.
Thanks to you and gambiting for providing what I guessed may be the benefits, I'm still confused about the feasibility. Can you prove something doesn't exist?
That is a problem. AFAIK it is possible to generate unspendable Bitcoin addresses without any private key in a way that could be revealed later (e.g. with a PRNG or deterministic wallet), but it's also possible that Satoshi generated normal key pairs and deleted them which would leave him with no way to prove that they were deleted.
That would (in a way) show the world that they created the currency for it to be a legitimate thing,and not just a scheme to make bitcoin popular and then cash in millions few years later. Or at least that's how some people would see it, if "satoshi" tried spending/turning into cash thousands of bitcoins he/she/they has/have.
Particularly if the unmasked progenitor(s) proved that they had actually destroyed the early Coins, that would help stabilize and legitimize the currency.