Having manually imported NX File New Templates into Teamcenter, using "File --> Import Assembly Into Teamcenter", the File New dialog continues to only show Manufacturing Templates having restarted NX.
Solution
In this particular case, a search was performed in Teamcenter database for the string "model-plain" and nothing was returned. On opening the Newstuff folder many new items were displayed containing newly generated numbers - typically indicating that Auto Generate had been used.
Starting with NX 10, the 'Auto Generate' and 'Auto Translate' options are no longer used when using the Import Assembly into Teamcenter dialog.
In order to import the File New Templates into Teamcenter and maintain the names of the files, so that the pax files retrieve the parts, set the following on the Import Assembly into Teamcenter dialog:
Default Settings: Name and Attribute Conversion
* Numbering Source: OS Filename
* Conversion Rule: As ID and Revision
Notes
Per the documentation:
OS Filename with Conversion Rule set to "As ID and Revision" is the same as the Auto Translate naming in previous versions of NX.
Notes