sell down from option exercise may not happen, page-9

yes, I would expect the people who converted to primarily be holders, but there may be some who failed to sell prior to the oppies being delisted and therefore had to exercise them otherwise they would have lost the lot.
There may also be a few that were not prepared to sell the oppies when they were trading at a discount to the shares after allowing for the exercise price.
In percentage terms, yes, you are correct about the returns expected, but in $ terms there may be a greater profit by holding the shares for a short term.
As further announcements of developments occur, those holders that were anticipating to sell in the new financial year, may elect to continue to hold as they re-evaluate the greater profits that are likely over the mid-term.