what i can discern is that this change by the king to the prince now in charge of the defense ministry is that he is the successor of the king. unlike great britain succession is by child. saudi has succession by the relationship to the king and whom will be the best fit by prestige, and the ability to do the job. generally in the past saudi history, there were assassinations and killing off potential rivals.
probably be more changes to come as the king is old,some suspect in ill health and wants his most trusted in position to prevent coup attempts from within.
Thank you , I have not been able to find any ties to him and the man in the hospital as of yet.