I always test new installs of SEE on my own laptop first.
I created a new set of MSI files for 8.2 MP2 and created a new admin account as part of the install.
After my PC checked in a looked at the accounts and it listed the old account from a previous install. The new one was no where to be seen.
I didn't know if this was by design or not. i just assumed that if you did an upgrade the new account would be listed.
I know you can set the admin account via GPO and will double check to make sure I am not overwriting with GPO, but just thought I would ask to see what others had found.