Even as a Premium Support document, I've only got access to the same release notes file, that indeed does refer to an unreleased 100.0.1 firmware. This is not really unusual though -- I've seen previous 9.9 and 9.8 release notes refer to unreleased firmware versions before they become generally available.
As an end-user, I've not noticed many changes in 100.0 firmware for standalone customers. It seems to primarily deliver the benefit of single SKU cross-compatibility with all Ruckus configurations (ZD, SCG, etc). Michael mentioned that this firmware might have a fix for standalone mode band-balancing.
I did notice as a bug/regression, my standalone AP now creates the "island-XXXXX" SSID's. But other than that, I've not noticed any performance difference or noticeable Web UI difference in standalone mode on 100.0 vs 9.8.1.