The new Cyanogen OS 12.1 update (based on Android 5.1 Lollipop) is expected to roll out for YU Yuphoria in India soon.
The company's co-founder Rahul Sharma (via Official YU forum) confirmed that the new Cyanogen OS 12.1 has entered final testing phase and has asked interested registered YU device owners to take part in beta testing of the firmware.
[Note: In order to take part in beta-testing, users must own a YU device, either Yureka or Yuphoria and be registered on YU forum (sign up, HERE). But at the time of filing this report, only Yuphoria device owners are being allowed to apply for beta-testing.]
He also added that the company has been receiving a lot of inputs (and also complaints) from the Yu Yuphoria owners for last few months. Taking cognizance of the major issues, the company's software developers have succeeded in auto re-calibrating the nagging proximity sensor bug and also fixed other issues such as gesture input and keyboard glitch to improve typing user-experience.
The company has also said that "entire camera stack has been rebuilt with reworked camera tunings." This is expected to improve camera enough to capture more detail under different lighting condition.
There is no word on when Yureka will receive the new Cyanogen 12.1 OS update, but going by history, the firmware release date is not that far away.
If tech savvy YU device owners are impatient to wait for the official update, YU and its software partner Cyanogen have given an alternate option by releasing the open-source developer firmware CyanogenMod CM12.1 nightly under code-names - 'tomato' and 'lettuce' for Yureka and Yuphoria respectively.
[Note: Though Cyanogen OS and CyanogenMOD are built by the same company, they are different; the former firmware is built by company's authorised developers who exclusively work with partner OEMs (Original Equipment Manufacturer) for a particular device, whereas the latter is created by global freelance and technically sound programmers certified by Cyanogen.]