one of the unclear steps for me: after 9 months fr

one of the unclear steps for me: after 9 months from the ipo, the company (Moscato) can convert at any time, without notice, a quantity of stock that he decides. If it were to decide, by hypothesis, to convert 20% of the shares, with what criteria would they be chosen? 20% of what everyone has in their portfolio? Obviously, if it reached 18 months and the mandatory conversion, this would lend itself to considerable arbitrage: for example, 10 days before the "expiration" of 18 months, causing the price of ngux to collapse, it would convert with a more unfavorable ratio for we holders of class a shares ...