Just to clarify, I understand the question as: Is it possible that the accumulation of bitcoins by successful participants in the Bitcoin economy will cause a liquidity crisis?
As suggested by the question and described in the answers of "Does hoarding really hurt Bitcoin?", individuals or institutions amassing bitcoins would reduce the supply of Bitcoin.
However, as the value of Bitcoin would increase to evade the demand pressure, the exchange rate would rebalance at a point where one could transfer the same value with less bitcoins, retaining liquidity at a lower supply. Should this trend persist, additional divisibility of Bitcoin might become necessary to sustain liquidity.
This form of deflation is a huge problem in regular currencies, as we live in debt-based economies: During deflationary periods debt becomes increasingly costly to repay, and similarly it becomes harder for companies to maintain wages of their workers as they are denominated in the same currency. Either the companies would have to succeed at contentious wage cuts or let workers go.
Today, Bitcoin is rarely used as a Unit of Account. Mostly, prices are displayed in other currencies and their Bitcoin values automatically adjusted to remain stable to the underlying price. As long as this remains the case, deflation in Bitcoin would cause little economic anguish. Deflation would mostly spell "investment opportunity". (See T. Lee's article 'No, Bitcoins Aren't In Danger from "Hyperdeflation"')
[Hereafter sheer speculation:] Should Bitcoin ever become widely used as a Unit of Account, it will be after significant portions of the global economy transact in Bitcoin. As it would be widely used, Bitcoin's volatility would have decreased and thus the value stabilized. Economic growth and technological progress would manifest in a sustained slight deflation. At that point, as investment opportunities would have to compete with the benefits of saving during deflation, the wealth accumulation of rich parties could strongly amplify deflation.