Apple has updated macOS Sierra to version 10.12.3, recommending the update for all users. Owners of the October, 2016 MacBook Pros will find that the update provides some fixes for their devices.
The update also provides a fix for a bug that prevented the searching of scanned PDF documents in Preview. Whether this resolves all of the many issues that we've seen with PDFs and Preview remains to be seen, and we'll update this post as we find out.
The update can be found in the Mac App Store under Updates.