This should do it I think (top of head code - not tested.) NOTE as written existing notes will be deleted.
Code:
Sub copyText_to_Notes()
Dim osld As Slide
Dim oshp As Shape
Dim strTitle As String
For Each osld In ActivePresentation.Slides
If osld.Shapes.HasTitle Then
strTitle = osld.Shapes.Title.TextFrame.TextRange
End If
For Each oshp In osld.NotesPage.Shapes
If oshp.Type = msoPlaceholder Then
If oshp.PlaceholderFormat.Type = 2 Then
oshp.TextFrame.TextRange = strTitle
End If
End If
Next oshp
Next osld
End Sub
To use Alt f11 to open code editor
INSERT > Module
Paste in the code
Run (f5)