Again, turning "mononoke hime" into "princess mononoke" isnīt re-interpretating/changing the original.
But it also fails to translate anything meaningful. Mononoke isn't a name... people don't realize it and actually think San is called (Princess) Mononoke because of that.

If they had done it right (even if they chose not to translate the meaning of Mononoke), you'd actually have to call the movie The Princess of Mononoke... or "Die Mononoke Prinzessin"