Also, if many wealthy bitcoiners will do it, that will really shake up the gold market and maybe expose all his manipulations, and manipulators..
Some perspective on this:
if 10% of the "value" of Bitcoin (1 Billion USD) was moved to gold, that would be around
25 metric tons (not even taking into account the price-depressing effect of such a sale on the BTC/USD markets).
Compare that to monthly gold imports of China:

So this would equate
about a weeks worth of supply for China. Hardly going to "shake up" that market.
If on the other hand 10% of golds value (650 Billion USD) was put into bitcoin, that would probably push
bitcoin price to around USD 85,000.
So if both things (bitcoiners diversifying into metals and gold bugs getting into crypto) happen to an equal extent, the effect on bitcoin will be much larger than that on gold.
That's a very interesting calculation.
No way can I see 10% of total above ground gold supply ever be moved into BTC though. That would include 10% of the central banks gold (if anything is left..), and above all of China's and India's supply, jewelry all over the world, etc... The Asians love their gold, and gold from China it is never coming back. Gold has too much of a tradition in these countries, and the West doesn't have much left...
But nevertheless, some shifting from gold into BTC could boost the price.