I agree with Thomas.
JF is a remarkable talent, totally unto himself and true to whatever he wants to attempt. There's enough documentation out there that shows how much he struggled with popularity and being so publicly facing.
The good thing for him is that he recovered his life back, and I think he owes as much to himself as he does Flea and Keidis for that much. There's a total brotherhood there and I am sure if he decided to come back they'd shitcan whoever was playing guitar at that time for him.