Since the release of the iOS 9.2, there has been no official jailbreak tool made on the operating system and most hackers were claiming that it is the case because they do not want Apple to just patch their exploit with another release. Shortly thereafter, Apple released the iOS 9.2.1.
Luca Tedesco also claimed to have jailbroken the iOS 9.2.1 and even shared some proofs of it online. However, he did not bother publishing the exploits and just told the hacking community how he did it so that they can also come up with their own exploits.
The final beta of Apple iOS 9.3 was eventually seeded by the American tech giant to developers and public beta testers which patched a jailbreak vulnerability of the beta 4.
Apparently, Apple made it so to make it a tad difficult to jailbreak the iOS 9.3. However, Tedesco claimed shortly after that he has already jailbroken the iOS 9.3 beta 5.
The full version of the iOS 9.3 was released late in March. While Luca Tedesco claimed and confirmed via Twitter that his code works on iOS 9.3 beta 5, implying that the OS is indeed jailbreakable, he refused to publish his exploits, making some think of it as suspicious.