What about using Word Languages collection which contains Language objects in PowerPoint macro? So you can get the Language-Name for the MsoLanguageID Enum values. Here you can find the languages Office is available in.
' Powerpoint code
' add reference to word lib.
Public Sub test()
Dim wordAppliacation As New Word.Application
wordAppliacation.Visible = False
On Error Resume Next
Dim languageId As MsoLanguageID
For languageId = msoLanguageIDArabic To msoLanguageIDSpanishPuertoRico
Debug.Print languageId & ", " & wordAppliacation.Languages(languageId).Name & ", " & wordAppliacation.Languages(languageId).NameLocal
Next languageId
On Error GoTo 0
wordAppliacation.Quit
Set wordAppliacation = Nothing
End Sub
Or maybe just like this in PowerPoint 2016:
Dim lng As Word.language
Dim lid As Long
For Each lng In wordAppliacation.Languages
lid = lng.id
Debug.Print lid & ", " & wordAppliacation.Languages(lid).Name & ", " & wordAppliacation.Languages(lid).NameLocal
Next lng