You have passive investors owning 20 G$ of that index, amounting to 20% of the total, 20% of each company, and 200 M$ per company.
You then rotate out a company for a new one. The index is still 100 G$, but to match the index you are contractually required to sell your 20% ownership of the old company and are contractually required to buy 20% ownership of the new company.
However, the newly added company only released 5% of its shares to the public and the founder kept hold of the remaining 95%. Those fund managers are contractually obligated to buy 20% of the newly added company, but only 5% is available. Like a short squeeze, where the squeezer buys and holds supply so there are not enough purchasable shares to cover the shorts (obligated ownership), this is a financial divide by zero.
To get the remaining 15%, which they are contractually obligated to acquire, they must purchase from the founder. As they are in violation of their contract if they fail to acquire the remaining 15%, the founder now has complete control to dictate any price they want.
That is the scheme described: how to short squeeze pensions who do not even have shorts for fun and profit.