An AutoNew macro or the corresponding Document_New procedure go in the template.
Run a macro automatically when a document is created, opened or closed
Assuming that the Document_New procedure is in the ThisDocument module of your template...
Code:
Sub Document_New()
' Charles Kenyon 2022-07-02
' Written by Charles Kyle Kenyon 2 July 2022
' assistance from Jezebel
' All Story Field Updater - AutoText fields - then unlinks
Dim oField As Field
Dim oStory As range
' On Error Resume Next
For Each oStory In ActiveDocument.StoryRanges
' This goes into headers and footers as well as the regular document
Do
For Each oField In oStory.Fields
If oField.Type = wdFieldAutoText Then
oField.Update
oField.Unlink ' this will no longer be a field
End If
Next oField
Set oStory = oStory.NextStoryRange
Loop Until oStory Is Nothing
Next oStory
Set oStory = Nothing
On Error GoTo -1
End Sub
This macro will update all AutoText fields in a new document created from the template and then remove the field leaving the results. If documents are going to someone else, you do not want these fields in the document, you want what they produce. This could be restricted to headers or footers but I know of no reason to do so.