Try something based on:
Sub MakeTC()
Application.ScreenUpdating = False
Dim StrName As String, StrExt As String, lFmt As Long
With ActiveDocument
.TrackRevisions = True
.ShowRevisions = True
With .ActiveWindow.View
.ShowRevisionsAndComments = False
.RevisionsView = wdRevisionsViewFinal
End With
StrName = .FullName: lFmt = .SaveFormat
StrExt = "." & Split(.Name, ".")(UBound(Split(.Name, ".")))
StrName = Left(StrName, Len(StrName) - Len(StrExt))
.SaveAs2 FileName:=StrName & "_TC" & StrExt, _
Fileformat:=lFmt, AddToRecentFiles:=False
End With
Application.ScreenUpdating = True
End Sub