You think that makes him sad? I would doubt that severely. I'll bet he's either got more sons or nephews, or at least a lot of cousins to remind him how great they all think his sons were. Islam has come to infect and destroy other cultures. They are trained to breed as much as they're able to with their furniture (wives).
I'm sure he already believes his sons could have not achieved a higher calling that to pierce the Americans with nails and iron, and that they will be enjoying their "virgins" shortly if not already. From here on, his family will gleefully look toward the grand numbers of jihadi recruitment for which those ANGELS OF DEATH will have been responsible.
He will kill himself and take others with him if not captured soon