Liquidating 200k BTC would be quite a sight to behold. For example, there are only 18k BTC of orders on Bitstamp right now: http://bitcoincharts.com/markets/bitstampUSD_depth.html
... meaning, selling 200k BTC would blow through the entire order book eleven times over. I have no idea how the market would react to that. I'm sure bitcoin would survive it, just like it's survived every other disaster, but it will be quite the rollercoaster.
The reason I say the 200k BTC would be sold off if the repayments are all in USD is because, if I remember correctly, Mt. Gox had almost no cash when it shut down. Most of its cash had been seized by the US government long ago. So if Mt. Gox are going to repay anything of significance, then it seems like those 200k BTC will be sold off. What's the alternative? Those 200k BTC have to wind up somewhere. I know nothing of Japan's legal system, but the alternatives seem to be "either the government ends up keeping the coins, or the coins are redistributed to Mt. Gox debtees, or the coins are all sold off and the proceeds are distributed to Mt. Gox debtees."
Anyone have any theories about what will happen to the coins?