According to this Kotaku post, Metal Gear assistant producer Ryan Payton has quit Kojima Productions, citing family reasons.
"Back when I joined Kojima Productions in 2005, I hit the ground running and didn't stop until we shipped Metal Gear Solid 4," he said. "Then, for the first time in three years, I wasn't working on any games and I had a three month vacation ahead of me.
"I went back home to my family's place in Washington state and literally three weeks after MGS4 launched we were hit with some pretty heavy news concerning my mom. I don't think I need to go into details, but all of this has reminded me about how important family is. So this past month I decided to leave Kojima Productions and look to continue my career working closer to my family in North America.
"It's not easy leaving my other family (the MGS team), but with everybody taking time off and not having any other big projects to shift focus to, it feels like this is how it's supposed to be. It's fate."
And yes, he does mention MGS5 over there. We salute you, Ryan. Best of luck.