Your right Pjanic should be more accurately described as a deep lying playmaker than a DM.He is always playing furthest back in a midfield three, so yeah that is accurate. His role and defensive duties might be different but position-wise he is certainly a DM.
Although occupying that dm space he does not carry out his role in the ndombele, Eric dier, kante sense of the word. Pjanic, Gundogan occupy that same DM space but execute the role more like Pirlo, with the emphasis on creating from deep rather than to screen and or destroy.