I am not really sure what your question is? You will need iTunes to sync the phone etc but what you use as your media player is entirely up to you. If you prefer WMP then use it. iTunes will ask on install if you want to use it as your default player,you simply tick the no box,or whatever is required,and continue to use WMP.
Honor 5X review: Hands-on with the new budget phone from Hauwei's young brand