i'd love to know this as well since i have the D7200 and was told if i upgraded to lr6 it would work....was not happy when it didn't
Same problem for Lightroom CC 2015.3. Looking forward to moment when D7200 will be supported.
It's not a "problem" - it's the way tethering support is always delivered.
You have to wait for Nikon to create a version of its SDK that supports your camera (and they've stuffed up their latest SDK royally); then Adobe has apply the relevant SDK code to Lr; then test it; then you need to hope that all of this happens to a timescale that allows Adobe to release a version of Lr with D7200 support this time round, rather than missing the next scheduled release, in which case you've got a few more months to wait.
Same every single time.
Oh - and you spamming every D7200 tethering thread to express your disappointment and impatience doesn't help and won't change anything, Marcel. You'll find out what's happening at the same time that everyone else finds out.