Perhaps I should make my argument more clear. The implied assumption is that the evolution will go:
Bitcoins -> paper Bitcoins -> central bank
I'm saying it's much more likely to be:
Bitcoins -> paper Bitcoins -> Bitcoins
Actually, what you say should be written as following:
Bitcoins -> paper Bitcoins by all banks (causes inflation and bank-runs) -> paper Bitcoins by Central Bank (establishment of
gold Bitcoin standard)
And after that we begin running into ever deepening economic crises which finally bring about dismantling of the Bitcoin standard (see the Great Depression), so the last step will be:
paper Bitcoins by Central Bank (causes deflation and incessant economic crises) -> fiat by Central Bank (Bitcoin standard dismantled)