Some guys thought that the "new" win8.1 ISO's released by MS on GA is a new compilation to replace RTM build 9600.16384, some refer it as RTM-2. And most people, already installed 9600.16384 and added RollupA updates, tended to reformat and fresh install with the new ISO's, thinking that it is something new and different.
I have downloaded the win8.1Pro X86 GA edition, let's see what's in it:
First I extracted install.esd to a new drive, by going thru installation(in a VM) and kill the process after expanding files, all this time web connection was disabled so nothing to affect it. Windows\explorer.exe reported 9600.16408, and system32\ntoskrnl.exe reported 9600.16404
Now, when installation is completed, open Control Panel ->Windows Update -> Installed Updates
Since there is no restore point, the 4 updates could not be un-installed, I am quite sure if it could be done, it would simply roll back to nothing but build 9600.16384, nothing more, nothing less.