We've been having 'repercussions' of one sort of another for years. Followers of a death-cult don't need a concrete, rational reason to blow themselves up in a Morroccan cafe or a London tube-train so I don't think his death will make the situation any worse. We've been told to be on our guard for a long time already and today is no different. 'Keep calm and carry on' as the phrase has it.
BTW.. Valhalla. There are pictures of the body circulating at the moment. The burial at sea complies with islamic rules about burial within 24 hours and also means his fans don't have a grave to turn into a shrine. I'm sure, if he's not really dead, he'll be popping up on our screens with a current newspaper in his hands to blow a metaphorical raspberry in our direction.