You can read the full official changelog below.
##Change Log Microsoft Weekly New Office updates are released to Beta channel subscribers on Windows, adding new features and changes. Microsoft is also expected to release a new Office Insider Build next week. If we find anything interesting in the update, we'll keep you posted. To update Microsoft Office Insider Preview Build to the latest version, open any Office program and go toFile > Account > Update Options > Update Now.
#In another Microsoft Office-related news, iOS users can now listen to documents while their iOS device screen is locked. Users can also open Office Mobile on their iOS device and tap Share with me to view all PDFs in Outlook.