Luca Todesco (@qwertyoruiop) has jailbroken iOS 9.2.1 according to his Twitter feed. Todesco posted a screenshot which appears to show Cydia running on iOS 9.2.1, the image snapped on his iPhone 6.
"I lied. All Hail í™”ê²©ìž ë¦¬ë”. No releases."
Translated to English from Korean means "Grate Leader"
Todesco also posted images of Kernel dumps to backup his claims:
As you can see the above image shows kernel dumps Kernel from iOS 9.2.1.
Of course there is no need to doubt these claims, Todesco was of course behind the Jailbreak of iOS 8.4.1 and contributed to the iOS 9 jailbreak that Pangu released earlier this year.
Do not expect a release of iOS 9.2.1 jailbreak anytime soon, at least not from Todesco and not until the firmware is out of beta.
If any jailbreak were to surface, it would likely be after an official iOS 9.2.1 release.
Chances are Todesco will share his jailbreak with teams like Pangu and TaiG as he has done in the past. Those teams would then look to release a full iOS 9.2.1 jailbreak tool.
The advice from Todesco right now is to stay on iOS 9.1 , do not update to iOS 9.2..