You do realize "Jihad John" has been pronounced dead 3 times right? I wouldn't be too surprised if they had just killed "what the assumed to be Jihad John" again in the next 5 months.
Nah. It's a reference to a British ISIS member, they named him after John lennon, because there were 4 big British ISIS guys, so the media named them all after Beatles members. His real name was Mohammed Emazi.