I frequently check Thom Hogan’s web site for news about Nikon cameras. He does a pretty good job of keeping Nikon owners abreast of what’s happening.
Thom’s Article on Nikon Updates (D800, 810, D7100, D7200, others)
Nikon has firmware updates available for some of the older cameras to make them compatible with the AF-P lenses. Thom’s site explains the problems and fixes.