Users found on GitHub a dossier proving that the CyanogenMod team is working on a ROM to the OnePlus 2. CyanogenMod 12.1 (Lollipop) and 13 (Marshmallow) are scheduled.
For a strange reason, the OnePlus 2 did not enjoy any ROM as CyanogenMod. This should take soon end, since as stressed a Reddit user, the CyanogenMod development team is working on a port of CyanogenMod 12.1 (based on Android Lollipop) and CyanogenMod 13 (based on Android Marshmallow) on the OnePlus 2 . the proof could not be more explicit: a file on GitHub owned CyanogenMod proves that the developers are working on it for several months.
CyanogenMod 13: all you need to know about Marshmallow ROM version
The OnePlus 2, unlike the OnePlus One, is installed under OxygenOS an Android interface developed by OnePlus internally. The OnePlus 2 well had had a few portages CyanogenMod since its release, but it was unofficial ports whose stability was questionable.
CyanogenMod has not communicated officially on porting its ROM on OnePlus 2. We do not know when the ROM will come out officially. They are in any case not yet available on the official site.