True. But that´s the same reason why Mendes will want to keep Newman.
Also, one could argue that despite Mendes´ association with Newman using Arnold as an established Bond composer would have been just as possible. The fact that Mendes did not want to rely on him speaks volumes. I know many directors who only work with their friends and cronies, never giving others a chance although these people are absolutely capable and qualified.
Of course, Newman is both as well. So, win-win for us. Not for Arnold, though.