I have a friend wo is connected to the GTAA as well. They are much more tight lipped since Batt took over, but I can confirm everything @AugustaSwarm has said here with one addition: not all of the interviews have been for defensive staff.
What I have been led to believe is that Key is expecting several coaches to either move on or be moved on, and is interviewing possible replacements.
Hoping that Buster, McKenzie and Weinke are all still here next year. I would love to see the improvement in year 2 in Buster’s system and I think Weinke is one of the more underrated QB coaches in P5.