It pretty clear, you are just refusing to see it.

His remarks about recovery of lost private keys are worded a little ambiguously but he doesn't say anything about "without a valid signature." [..] We know that technological advances will eventually make it possible for current private keys to be cracked. He seems to be suggesting that we could turn that into a miner incentive as an orderly way to bring the coins back into circulation.

The key word is "miner incentive". (I am referring to to lost keys or burn addresses here: not OP_FALSE: these cannot be claimed with a valid signature in anyway)

If it becomes feasible to break or brute force old private keys then at some point, someone will claim them with a valid signature. You cannot decide in advance "these coins are lost and in danger of being stolen".

If a miner dedicates hash power to brute force keys, this is perfectly acceptable and in fact similar to old ship wreck salvage operations (you are expending resources to reclaim value that is difficult to access). BUT in the process you are not a miner, you are a "treasure hunter".

If CSW is referring to the above then no problem, although he would have said nothing new though.

But, since the post is about "bringing coins back into circulation in an orderly fashion", what he is probably referring to (how conveniently ambiguous! it must be because of the secret master plan!) is that at some point, lost coins will be deemed "lost" and miners will be able to claim them through some pre-determined schedule (for example coins that haven't moved for 200,000 blocks).