According to Cyanogen, Android 5.0-based Cyanogen OS 12 is currently in the QA/QE stage for both phones and it will soon begin soak-testing for the Yu Yureka users in the Indian market. There seems to be no plans of the soak tests for the OnePlus One update.
The company also revealed that it is evaluating the changes present in the new Android 5.1 and will release a separate update with these changes. There is no word on when this update will arrive.
OnePlus One and Yu Yureka are the only two smartphones with Cyanogen OS in the market right now. Alcatel OneTouch Hero 2+ will join these phones in the coming days, but it is yet to go on sale. Cyanogen team noted that Hero 2+ will arrive with Android 4.4-based Cyanogen OS 11 and the company is working with MediaTek to get the Android 5.0 update, which could be released around May or June for the phone.