Today Apple has seeded its second beta of macOS 10.12.1 to developers. We’re unsure what’s new in the beta but we’ll keep you updated if we find more information.
The update is currently available for only developers. It’s not recommended to install this beta unless you’re an actual developer as there’s no reverting back without data loss.
Those with access to the macOS developer or public beta can download the update now in the Mac App Store.