I do think other exchanges will want those transaction fees, absolutely, and will start to court users of Upbit who may want to jump ship.

The situation with Upbit is known for a bit, at least by insiders (the notice was received on January 9th), and nothing drastic happened. I don't believe whales are in the business of crashing the price of their holdings, particularly when it's nothing wrong with them, only potentially with the exchange. They find smarter ways.