It certainly was in one of the early 10.2 nightlies that I tried.
It's a kernel source change, so I'm not sure what this implies about whether recent changes to the (stock) 4.3 kernel are being merged into the CM kernel sources.
Here we provide information, patches and a few system images to support Ad-Hoc (IBSS) mode. We base our additions on CyanogenMod 10.1-M2 (Android 4.2.2 JDQ39).
Our goal is to bring the missing Ad-Hoc (IBSS) mode to Android, in a way that is completely integrated into the Android system API and user-interface. Users should be able to create and connect to Ad-Hoc networks from the standard user interface (Settings – WiFi) and Applications should have an API to configure their “own” Ad-Hoc network. We believe this will help people who need more capability than WiFi Direct and can extend diverse usages of Android mobile devices.
To achieve this, we have modified the WLAN driver “bcmdhd”, extended the Android framework, the public Android API and added the missing parts to the “Settings” application. At this moment only Nexus S, Galaxy Nexus and Nexus 7 devices are supported and tested, but the same kernel modifications can be made to a number of devices and the UI will automatically show Ad-Hoc mode options when the driver supports it.
We have submitted these changes to CyanogenMod and Google AOSP Gerrit and provide this page for further information.