This update has now gone live for multiple regions, carriers. You can discuss more in the CrackBerry Forums.
Now that Android Marshmallow has been officially released for Priv owners, BlackBerry has already begun working on the next steps for that OS. As announced alongside the app updates for Priv today, Michael Clewley, Director of Software Product Management at BlackBerry let it also be known that BlackBerry has plans to start rolling out a software maintenance release for Priv owners starting on June 6.
The update will be pushed in alignment with BlackBerry's standard monthly security release, so the June update should be larger than previous months. For now, that's all the details that have been noted regarding the release, but kudos to BlackBerry for letting everyone know ahead of time.