Each of the contracts has different terms.
BUG4 (BTC/USD-2.14) settles Feb 21st, and gets price based on the volume weighted average price (“VWAP”) across the three operating exchanges with the most volume in BTC-USD over the previous 30 days.
So eyeballing the BitcoinCharts data, looks like Mt. Gox will definitely be one of the top three over the past 30 days (in terms of BTC/USD volume).
Now what impact Mt. Gox will have on settlement day will be determined by the (24 hour) VWAP at Mt. Gox at the settlment time (20:00 UTC) on that day. So if the top three (volume of BTC/USD) are Mt. Gox, BTC-E and Bitstamp and the (24 hour) VWAP at each is 600 (Mt. Gox), 750 (BTC-e) and 750 (Bitstamp) then the average of those three is 700 (2,100 / 3) and that becomes the final settlement price.
Now BUH4 (BTC/USD-3.14), which settles March 14th, uses the 24 hour VWAP from the exchange that had the most volume (in terms of BTC/USD) over the past 30 days. So this time, eyeballing the data, it looks like Bitstamp would be the exchange with the most volume. And thus, no -- MT. Gox divergence would not impact the settlement price.
And BUJ4 (BTC/USD-4.14) specifies the exchange (Bitstamp) so there too Mt. Gox divergence would not impact the settlement price.