Since BNB is not part of decentralized crypto industry rather a centralized coin. So its nothing new that its supply or other parameters can be manipulated by Binance.
Binance has everything now, both a centralized exchange and Dex both of which are doing very well, so there's no reason to manipulate this on their own because they basically want to grow like the others.
I have to admit that the team from BNB is the best right now, they are always making innovations to make anyone not hesitate to invest in Binance, I am sure that Binance will dominate the market in the future especially now that many exchanges that Binance acquired are making their position in the global even more strong.