The bigger problem is that it would take a full year for everyone to migrate to the new quantum resistant wallets at current block size limit, so even if there is just-in-time forced consensus on a solution, it's still going to be too late to avoid chaos.

We need to be more or less agreed on a uncontentious and well tested solution 10 years before a quantum breakthrough.

Thankfully there are lots of eye balls in this that are not those of Bitcoiners, so as long as most big breakthroughs are published and widely propagated it'll be well telegraphed.

Still, plenty of scope for everyone to accuse everyone else of being a psy-op agent.