Unless Kelly goes through a metamorphosis, the changing of anything but the OC or DC is just shuffling the deck chairs on the Titanic.
The notion that new coaches are going to make players better when it is the scheme and play calling that is the problem is inane. For example, Heistand doesn't go from producing pro players to sucking in one year. As to ST, results are because of emphasis placed be head coach, not the coaching. Kelly places no emphasis on them so a change in coaching won't do a thing to outcomes.
Assuming the BK is the coach in 2017, he will be viewed as being on a very hot seat unless the team goes undefeated the rest of the way. Given that, his choice of coaches will be limited. He isn't going to be able to attract of DC outside of his coaching tree so I wouldn't be surprised if Hudson ends up as DC. He has nothing to lose and won't be in big demand. Unless both Denbrock and Sanford leave, he won't be hiring a new OC. If Denbrock stays, Sanford leaving would not be a surprise. If Denbrock does leave (which would be surprising since he doesn't seem to be in much demand). Sanford might stay to be OC but he might get better offers.
There will undoubtedly be changes because there are every year. But other than VG, new coaches aren't going to transform the team.