Apple Is Releasing macOS High Sierra On September 25 (techcrunch.com)
After updating its website for the iPhone launch event, Apple has confirmed that macOS High Sierra will be released on September 25th. TechCrunch provides a brief rundown of the major changes, most of which are under the hood: The Photos app is still receiving some new features to keep it up to date with the iOS version. There are more editing tools, you can reorganize the toolbar and you can filter your photos by type. If you're a Safari user, my favorite change is that there is a new feature in the settings that lets you automatically block autoplaying videos around the web. Many websites have abused autoplaying video, it's time to stop it. And then, there's a new file system that should make your Mac snappier if you're using an SSD. Mail is compressing messages, Metal 2 should take better advantage of your GPU, Spotlight knows about your flight status, etc. The free update to macOS High Sierra will be available in the Mac App Store.
Well, if you're so worried, then you shouldn't upgrade ot High Sierra then on your production systems. Which is never a bad idea since the bugs on a .0 release of an OS are huge. You can hold off until .1 or .2 is released which should fix a bunch of the biggest issues.
Apple will retain support for the previous version of the OS until at least the next version of the OS is released, so you can hold off and wait for the bad news.
And Apple has nice backup tools for you too - Time Machine will be useful enough to handle a pre-upgrade backup.