...
The only way I would be ok with coins being locked or frozen would be if there was some method for the true owner to prove their ownership and reclaim them.
Exactly. Therefore, if someone else then Satoshi is able to move Satoshi's early mined coins, so Satoshi has to react.
When objects of value are found in a ship wreck at the bottom of the sea, should those that managed to find the wreck be allowed to profit from that find? Or should a government agency take evderything salvaged and destroy it?