600k-700k is the same guess as 1million bitcoin was. it doesn't matter how much they try to "analyze" things, in the end they will be making a big guess with a large margin of error because nobody really knows how many people and who have been mining bitcoin in the early days.

and it wouldn't make any difference. that is still a lot of bitcoin, in reality it won't affect anything since they won't come into circulation and even if they do, Satoshi is not someone who would dump on the market but people have their own weird reasons for panic.