I wish this were the case & I think that this would be fair because most fiat holders were only holding fiat by chance and would probably have been in coin if the timing were slightly different.
However I think they propose to set the conversion date once the exchange is up.
"With a balance of 1000 USD, after conversion you will receive 55% in BTC, LTC, ETH (at exchange rate on the day of conversion) and 450 USDET. By this principle all koins and fiates will be converted. "
It sounds like a reasonable proposal, the first few days of trade will be exciting, I would imagine a lot of people will want to withdraw their 55% in crypto asap out of fear that the exchange may go offline again, however the BTC-e admin sounds pretty serious if they have a legal team and backing from and investor. Didn't see Gox or Cryptsy make an effort to keep going like that.
Trade in the exchange tokens need to do their price discovery. I have seen exchange tokens do very well in the elsewhere. USDET could be a popular hedge like Tether. I will be keen to see how well they trade.