The leaked document indeed had the right dates and as it says, Android 4.3 update for Sprint Galaxy S4 should be live today and it really is. It has been confirmed that Android 4.3 update for Sprint Galaxy S4 is rolling out as seen in the screenshot below:
Also, it can be noted on Samsung’s support page where it says that the update has been release on 30th of October.
The Android 4.3 build L720VPUAMJA weighs 537 MB and it makes your device compatible with Samsung Galaxy Gear smart-watch. Apart from this, the device will also have KNOX enabled that makes rooting quite difficult, however it can be bypassed.
If you don’t see a notification for the update, you can go to Settings>About phone and check for software updates. If you see the build number mentioned above, you can be sure that it is the Android 4.3 update you are looking for.
Since the update just started rolling out, it isn’t available for download online but it should be uploaded soon somewhere on XDA forums.