The similarity of the numbers does not mean that the theory is correct, as you cannot support your argument with anything logical to accept it as a theory. You can support your theory with quotes from Satoshi, but they will all be a matter of speculation and there is nothing to actually support them.
Quote from Satoshi
I think the traditional qualifications for money were written with the assumption that there are so many competing objects in the world that are scarce, an object with the automatic bootstrap of intrinsic value will surely win out over those without intrinsic value. But if there were nothing in the world with intrinsic value that could be used as money, only scarce but no intrinsic value, I think people would still take up something.
(I'm using the word scarce here to only mean limited potential supply)
The most acceptable explanation is the Fibonacci sequence 0, 1, 1, 2, 3, 5, 8, 13, 21, and the number is not 21, but 20999999.9769 BTC.