The stable and beta releases are announced in the forum under the Announcements category. Ths is a good category to set to Watching (top right corner). Snapshots of openHAB-Distribution and opeHAB2-Bundles are usually built nightly. The zwave binding also has a development branch, that Chris distributes builds from about weekly in this thread (link in the first post). If you’re willing and able, you can build any of these yourself too.
The NZW39 changes to the device database should be in the snapshot build of the zwave binding (included in the OH snapshot build) and the dev binding. Since you are currently running an OH snapshot, you can uninstall the zwave binding and reinstall to get the latest version of the zwave binding. Or you could update to the latest OH snapshot.