> In exchange for such favorable terms (i.e., small carrying cost, matures on death), the bank will receive a share of the collateral’s appreciation (essentially amounting to “stock appreciation rights"), and this obligation will be settled upon the borrower’s death.

It's a loan in name only.

Regarding Bezos's selling of stocks - perhaps he has offsetting capital gains. See https://old.reddit.com/r/BuyBorrowDieExplained/comments/1f26...