Microsoft has been steadily marching towards getting familiar desktop features onto their mobile apps. Most recently, that meant support for versioning, auto-save, and live collaboration. This time around, all three get the ability to export to PDF, something we take for granted when using the full versions of Office. They also get a new feature allowing users to insert images directly from your camera, which of course is a feature more unique to mobile. For its part, Microsoft Word for Android can now open RTF files, which falls into the "I didn't realize it couldn't already do that" category for many of us.
The headliner, of course, is PDF export. This is arguably becoming more critical as the office suite market is getting more fragmented. Rather than worry about whether your document will format correctly when opened in [insert app here] on [insert platform here], PDFs reliably render the way you want them to. Both Word and PowerPoint users stand to benefit from this; Excel gets the capability as well, but is probably lower on the list of wanted features for its users.
The method of converting the file to PDF is peculiar. As Microsoft tells you when sharing the file as a PDF, the change actually happens on Microsoft's servers. They assure you that the file is not stored there, but it does strike me as an odd security and privacy vulnerability. This is also the way RTF files are handled; in fact, Microsoft's support says this is how any non-OOXML format file is dealt with and is a necessary step for printing too.
Beyond just being a little bit outside the norm, it also means you need internet access to use any other file type. If you wanted to work on your tablet during a flight, for instance, you would have to do all those conversions ahead of time. Still, this is better than nothing!
The application versions for each app after these updates are 16.0.6729.1013. Most users should have received the updates through the Play Store by now, but if not you can always grab them at APK Mirror.