All the gold that has been mined has been saved up.
There is at least 10x the amount of gold stated as "all the gold in the world" in vaults.
If this gold hits the market it will be like, "do you have a good use for it, so as to bother me to go into the vault to get you some"

There is tons of gold in the Grand Canyon
There is tons more in the Chocolate Mountains.

And there is tons more hidden in caches all over the world.
And piles of it at the bottom of the ocean.

Further, in the future, we will just be able to vibrate it out of rock.
Almost no mining cost.