A leitmotif or Leitmotiv[1] (/ˌlaɪtmoʊˈtiːf/) is a "short, recurring musical phrase"[2] associated with a particular person, place, or idea.

I don't think any of DTs recurring musical phrases are "associated with a particular person, place, or idea." Like there has to be more to it than recurrence to be considered a leitmotif. Recurrence in music happened a lot for various reasons before the idea of leitmotifs, so if you use the term generically to that extent it loses any meaning.