we execute the "generalize" command, and reseal the os for the out of box experience. therefore the local admin account will be replaced.
what you could do ... is write a post customization script to execute those commands instead of leaving them with one on the desktop.
that way, the windows system would be activated by the time the users even gets to it.
@echo off
if "%1%" == "precustomization" (
) else if "%1%" == "postcustomization" (
---- right here you might want to run a ping test to the DNS/IP of your KMS system to ensure you don't try and register when the system is not reachable
cscript \windows\system32\slmgr.vbs -skms ...
cscript \windows\system32\slmgr.vbs -ato
)