True, but it requires user to use vulnerable software. Reusing
k value (also called nonce) is well-known problem, so it's unlikely you could someone private key that way.
The decision also won't be unilateral, whatever the decision may be. It will be a fork that like any other fork requires support from the majority.
I meant unilateral in respect to the owner of the coins. The majority shouldn't get to decide what to do with the coins belonging to someone else, even if we think those coins have been lost or abandoned.
Unfortunately people have different opinion on this matter. For example, few people think it's better to freeze vulnerable UTXO rather than letting thief stole it and potentially manipulate Bitcoin price.