Pretty disappointing if you ask me. The entire gold vault (one million ounces of gold) is worth about a third of one percent of JPMorgan Chase's entire market capitalization.
The only thing that's safe to assess about that bullion is that for all human intents and purposes, it'll outlast infinite numbers of generations, and the other stuff --- won't. That alone tells of the impossibility and futility of putting any sort of currency number on it, in fact, any figure will do --- $100 or $100k, whatever the world perceives will be equally valid and equally workable. Doubly so since "you can't eat it", it's in the final consequence not broadly "needed at any price" for industry, and the actual supply for its prime purpose (preserve some proxy of wealth through the generations) need not be increased, and every physical ounce above or below ground is in extremis already owned by someone.
Revealing a "problem" with US-held gold would be a blow to US currency dominance. The value of such a shift in global power is vastly more than the total value of gold on the planet, which is about 8-9 trillion US$.
In other words, gold is nowhere near able to become a currency substitute, but it is potentially a bomb that can damage the dollar.
A good example to consider is aluminium. In early 1880s, the price of aluminium was around $10000 of today's dollars for kilogram -- actually the price of ounce made more sense, as you very rarely saw pieces of aluminium so large to weigh a kilogram back then. For example, the capstone for Washington Monument, weighing 9 kilograms, was the largest single piece of aluminium ever cast at that time.
Then, in 1888, the modern process of aluminium was invented, and soon its price rapidly fell by orders of magnitude.
What is it about gold that triggers wild conspiracy theories from seemingly rational people?
Is there a cliff where gold as a store of value just starts crashing? Or would the fantasy continue for the non-institutional holders for a while?
Most central banks have foreign reserves ( https://en.wikipedia.org/wiki/List_of_countries_by_foreign-e... ) and and central banks' gold reserves are typically less than 1% of their reserves. So gold backing any currency is just a small part of all gold in existence (about 170 000 000 kg ~ 7T USD)
For "all currency", the money supply is a lot (converted to USD): US M0 is 10T, UK 2.85T USD, Eurozone ~8T, Australia ~1.8T. And China, Japan, India and so on also has big monetary bases.
You CONVERTING gold into USD on a current value. But rest assured if one million ounces are rendered untouchable for period of 100 years due to radioactivity, you can bet your bottom dollar the price of gold (remaining stock) will sky rocket.