SQL Server Installation - TempDB not created in the directory specified in ConfigurationFile.ini
I can't say specifically why but when reducing the initial size of the TempDB files, they were created in the directory specified in the ConfigurationTile.ini.

I updated the ConfigurationFile to the following:

; The number of Database Engine TempDB files. 
SQLTEMPDBFILECOUNT="8"

; Specifies the initial size of a Database Engine TempDB data file in MB. 
SQLTEMPDBFILESIZE="256"
; Specifies the automatic growth increment of each Database Engine TempDB data file in MB. 
SQLTEMPDBFILEGROWTH="0"

; Specifies the initial size of the Database Engine TempDB log file in MB. 
SQLTEMPDBLOGFILESIZE="256"
; Specifies the automatic growth increment of the Database Engine TempDB log file in MB. 
SQLTEMPDBLOGFILEGROWTH="0"

; Directories for Database Engine TempDB files. 
SQLTEMPDBDIR="T:\Data"
; Directory for the Database Engine TempDB log files. 
SQLTEMPDBLOGDIR="T:\Log"

; The Database Engine root data directory. 
INSTALLSQLDATADIR="O:\Data"
; Default directory for the Database Engine user database logs. 
SQLUSERDBLOGDIR="O:\Log"


As an additional setup step, I'll run a script to re-size the tempdb files.