In the short term, sure.  The holders indirectly liquidating, forcing the price of Bitcoin down.  However, you are overlooking the role that money velocity will play.  People will revert to converting USD -> BTC instead of liquidating their BTC savings accounts.  This velocity will end up driving the price of Bitcoin higher due to the lag between inflow and outflow per transaction.  Beyond this, major retailers jumping on board mean that powerful people have a vested interest in Bitcoin, potentially mitigating the threat of future regulation.  If you position the powerful to benefit from a technology, they are unlikely to regulate it.