It will not happen because the BSC chain is not fully decentralized. The entire chain is under control of Binance and the nodes are run by 3rd parties which are controlled by Binance. A complete switch to the Binance Chain would mean for a project or company to be in the clutches of Binance which is an business risk.
Why can it be a business risk if the company is in the grip of Binance ? because so far I have never come across bad news for Binance and its followers or the companies that have worked with it for a long time.