A) it is far easier to mine a block of Bitcoin than it is to randomly generated a valid private key. Unless the Chinese team thinks they know something that could help them with a shortcut, thinking that the PRNG in sayishis computer was flawed somehow.

B) knowing that it's far easier to mine a block than it is to guess a key, and realizing that sayishis coins haven't been consolidated in anyway, why devote that much computer power for a 50Btc reward (the amount in any of satishis addresses), why waste the energy when that same compute power could be used to generate far more than 50Btc?

C) assuming the go ahead and mine one of satoshis addreses, then there goes Bitcoin. If one if his the private key for a random address can be recovered somehos, then that would mean that none of our coins are safe. Don't get me wrong, if it's possible to do Then absolutely they should do it, just so the fault they're working off of or discover becomes well known, giving everyone the chance to jump ship, rather than take such an invention and use it for nefarious purposes.

Overall, on a threat scale of 1-10, I'd rate this minus 10.