YU has released four phones as yet, YUreka, YUphoria an YUreka Plus, YUnique all three came with CyanogenOS with guaranteed update and probably this is was main reason why many chose an YU phone over another stock android smartphone.
The phones were and are still sold online, exclusively on Amazon and YUnique is sold on Snapdeal. Recently the Yunique, YU's budget smartphone came available on stock android, no CyanogenOS at all.
And a few days later all the available smartphones of YU with CyanogenOS became unavailable and now comes with stock Android.
What Special in CyanogenOS?
CyanogenMods are ROMs that can be flashed on almost any phone, but CyanogenOS is built to function perfectly with a phone and that is why people loved the YU phones and so do I, as a I own an Yuphoria with CyanogenOS 12.
Wouldn't be Cyanogen available for us?
You don't know how to flash ROM? No worries, YU will help install CyanogenOS 12 from 825+ service centers around the country.
So really Cyanogen is no longer available with YU?
We did a small research to make sure it wasn't true and what we find doesn't leave any hint of them breaking ties.
The official CyanogenOS web page still displays the YU phones with CyanogenOS in the list of their CyanogenOS phones: https://cyngn.com/get-cyanogen-os
The model of the phones with stock android are suffixed with an "A", whereas the initial model name is still in use and it says it comes with CyanogenOS
New CyanogenOS 12.1 is coming
On the contrary YU has announced the release of CyanogenOS 12.1. It will be soon available on all YU phones with CyanogenOS 12 as an OTA update.
Don't worry just get your phone.
Also be sure to check for ongoing deals on these phones. Recently Yuphoria (with stock Android) is now being sold for Rs. 5999 in an lighting deal. Check back to get deals and offs.