It will be very difficult to reach a consensus either way, as there are strongly held beliefs on both sides. I am very much of the opinion that it is better to let these coins be stolen than it is to do anything to lock them or make them otherwise unspendable. It is better to take the short term price hit from lost coins re-entering the market than it is to destroy a core principle of bitcoin and allow a small group of devs or a small subsection of the community start to decide what happens to coins which do not belong to them.

It is worth noting that not all vulnerable addresses will be hacked at once, but rather, it will happen gradually over months or even years. There are a multitude of reason in which coins which are not lost may not move for long periods of times. Perhaps the owner is in a different country to their wallet. Perhaps they are in prison. Perhaps the private keys are locked up in some kind of inheritance or trust. Perhaps there is a timelocked transaction waiting to be broadcast at a certain date. If we set a fixed date and lock all these coins, then we will absolutely be depriving some users of their coins against their will. At that point, bitcoin is no longer decentralized not trustless.

If you are careless and fail to look after your private keys or move your coins in time, then they will be stolen. Far better that than the devs say "Since you are careless, we are going to take your coins away from you." You can't be your bank if someone else can unilaterally remove that privilege from you.