I don't see how that dragon would come to that conclusion logically? I would think he'd just be amazed that they all finally realized they had green eyes *somehow*. And the fact that he didn't, would reinforce even more that he probably doesn't have green eyes. Regardless, logic would not...
BTW, as we know, if one of the dragons missed your farewell announcement, in the puzzle as stated, everyone stays dragons.
How many dragons would have to miss the announcement if you told them "at least TWO of you has green eyes" for them to all remain dragons?
And if you said "at least THREE"...
Another way to get at this is to first take a simpler case, where you say "at least 99 of you has green eyes". What happens then?
Then what happens if you say "at least 98 of you has green eyes"?
And now, if you really want to test your understanding of this puzzle, answer this: What happens if you tell them all that at least TWO of them has green eyes? What about if you tell them at least THREE, FOUR, etc has green eyes?
First thing to point out is that every dragon knows that all the other dragons have green eyes.
What every dragon does not know is whether or not he/she has green eyes.
So, you can imagine, every dragon lives his/her whole life wondering whether he/she is the one lucky dragon without green eyes...