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 and 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.
I agree with that. Let's say there are even 2-3 mil. coins that are lost (nobody has private keys anymore). If the stealing lasts 10 years it's like mining with current block subsidy at that time (approx. 328.500 BTC is currently mined per year).
And to be honest, I don't think that many coins are lost and thus would stay on vulnerable addresses.
Of course, if the attacker manages to crack keys from dozens of thousands P2PK UTXOs within a couple of months it could be disastrous (pricewise).
FYI: there is currently 1.73 mil. BTC on 48.000 P2PK UTXOs.