Regardless of the claims of Apple that its iOS cannot be jailbroken, the Chinese jailbreaking teams from the likes of TaiG and Pangu, among a few others, simply have what it takes to do it. While jailbreaking iOS before often takes days, nowadays, it is just a matter of hours.
And often, it is not just the jailbreaking teams from TaiG and Pangu who are doing it. Some hackers have also learned the trick. And once they share it to the internet via TaiG or Pangu, it becomes open to anyone who has an iOS device.
Because Apple was somehow shamed by the jailbreaking community when it said that iOS 9 cannot be jailbroken yet days later, a Pangu iOS 9 jailbreak came along, it had to redeem itself and took away the exploit by immediately releasing the iOS 9.1.
But as expected, the iOS 9.1 was jailbroken again so Apple had to keep the cat-and-mouse game going by releasing the iOS 9.2.
The iOS 9.2 jailbreak immediately arrived shortly. So Apple had to rethink of another strategy to outsmart the jailbreakers.
The American tech giant decided to sow confusion by releasing two iOS 9.2.1 betas, hinting that it is the next public release. However, for some reason, Apple decided to abandon the iOS 9.2.1 beta without any explanation and instead, the tech company decided to send the iOS 9.3 betas to developers and public beta testers in the middle of January.