Whatever the circumstances, there's going to be a lot of split opinions when it comes to the proper discussion definitely.
Which is why I think what will probably happen is the scenario I've described above, where lost coins are gradually stolen are re-enter circulation. If we can't reach a consensus on some other solution, then this is the default position which will happen if we do nothing, as Adam_xx points out above.
Irrelevant arguments here because we are not talking about some "arbitrary reasons" we are talking about a serious one that would make the very thing that made bitcoin secure becoming obsolete.
It's not all about price either, in fact not preventing old UTXOs from being spent would be against the fundamentals of bitcoin where your coins are only yours to spend not everyone's.
I disagree. If the community can decide that you cannot be trusted to look after your coins and move them to a quantum resistant address before they are stolen, then the community can also decided that you cannot be trusted when it comes to any other scenario, and can therefore censor you.