It says so right in the article. People would flood the market with cheap/counterfeit Raspberry Pis and the organization would be on the hook for support.

I have not seen any evidence of "flooding". Just a couple posts about it. And one of those posts was saying theirs did work with the old firmware, so for that instance the Pi folks deserve the full blame for adding a check that disabled booting.

I also don't see any mention of it in this article?

They have to plan their production in advance, with budgeting, contracts, and prices decided before the products are even manufactured. This is hard to do even when you're just trying to plan for the demands of legitimate buyers.

But every single day in the meantime, RAM prices will continue fluctuate, and arbitrage takes advantage of this. And arbitrate markets don't even necessarily track new RAM prices, if someone dumps a bunch of used LPDDR devices in China, people may harvest used memory for arbitrage.