I doubt those missiles will ever be destroyed; the mentality of the Chinese leadership has changed, for the better. America is now seen as a long term adversary and not a partner. This is a civilizational clash.
For wartime production, refer to America’s industrial transformation when they formally joined ww2 and established the War Production Board. Car factories turned into tank factories, nail factories made bullet cartridges, etc. Literally every non-essential assembly line in the country was making weapons.
This is what truly scares Americans, because they know with China’s current industrial capacity, number of shipyards, factories etc. a conventional war of attrition isn’t in their favor.
I hope you are right. I was for several years totally not amused during the Trump administration with the Xi administration.