New firmware upgrades for WT-7, D810, D500, D750, D7200 and a few days earlier, SB-5000 have been released. Mostly it seems about bug fixes and added compatibility with WT-7 to these cameras. I had an occasional problem with the 300/4 E and D810 where the first exposure of a series was not correct, and I speculated what could be the cause of it; the firmware update explanation suggests that right after changing lenses the exposure may have been incorrect, and this issue was fixed. There is also a mention that sometimes images taken were not stored. I can't say I remember that kind of a situation but it may be that I have forgotten that I took an image which was not stored, though I think it's more likely that this is a very rare event.
So now one can use the WT-7 with D500, D810/D810A, D750, and D7200, but there is no firmware fix for the missing tripod socket at the base of the transmitter.
I guess it is a good thing that Nikon makes this transmitter work with several cameras, and for studio use I guess this device would work well since it would be used in place of the vertical grip. But I think when paying for such an expensive accessory, it would be nice if they provided a useful way to mount it on a tripod, when using the camera with remote control. I guess it would be possible to machine a suitable mount, or use some kind of clamp for mounting, but it seems strange to have to go into a custom solution for such an obvious application.
The D500 update seems to be about making Snapbridge connections more reliable, but they only mention issue in conjunction with a specific version of the Snapbrigde application for a specific OS (iOS 10.2). Well, at least they are issuing updates.