I saw this poll in a Mt Gox sub-reddit. It may not be as bad as we thought.
The result of this poll is not even close to the total number of people that are to benefit from Mt. Goz as they set to return assets to users for over a decade now. They are genuine voters that will benefit from the returned asset but for not having the total number of people to benefit from it not voting, then it could as well be that they are almost certainly (about 90%) going to sell their bitcoins when given.
The sale of the German government was also met with a lot of people judging their move, you'd see articles everywhere which may have caused a larger mayhem than it actually was. You're saying people might panic because of the news, what kind of news are those that are going to create a chaos in the market? Old investors from selling the Bitcoins owed by Mt.Gox since 2014? Probably not, and even if it does happen, the effect will be minimal.
Sell of bitcoins by Mt. Gox beneficiaries will not cause the market to crash that much because I don’t see that many of them will want to sell it, even if they do, it’ll be a little quantity. If they’d wanted to hold their bitcoins till now, they might not have that patience. Over the years, the closing price of bitcoin as of 2014 was just $320 and today bitcoin is currently trading around $64K and have rose up to $70K+ in this year only. With this, not all of them will want to sell all as it shows how prospective bitcoin will be in the coming years and the bull run fast around the corner to see another all time-high of bitcoin.