Price drop then would not be necessarily just from the Gox or ones that bought in Gox cheap selling... Other people will follow selling... actually it's happening right now... 8.87 price decrease in one day... that's not Gox price on coinmarketcap.com
Sorry, but you haven't given any valid mechanism that's going to equalise the market on gox and the external markets without gox reinstatating their withdrawals or otherwise regaining the public confidence. Gox has dropped much further than the other markets over the same day, so your final observation doesn't support your point at all.
Well, please read what I wrote again. Gox and external price should find equilibrium somehow with a positive or negative offset after gox enabling withdrawals. Much or less that's what I said. A good news is a good news for all but the existing trend will be reversed. After the good news gox will increase and the other markets will just decrease. Then it's all about what's unknown in the story and the look to the general reception of bitcoin will determine the market price at gox and elsewhere.
Why does Gox allowing withdrawals create a massive price drop on the external exchanges? If anything I would expect them to trade up on such an event, not down, but in any case the vast majority of the equalising price changes would take place on Gox, not on the external exchange.