No confirmed root method so far, that I know of. The developers will find it when they find it, no use asking for an ETA..it happens when it happens.. Having helped find root on a device before, myself, I know how frustrating and time consuming this process can be.
(Excerpt from SRSRoot website)
2016-12-16 06:06:05 ZTE Z815 Z815V1.2.13 6.0.1 msm8909 Permanent Root
2016-12-16 06:04:45 ZTE Z981 Z981V1.0.0B08 6.0.1 msm8952 Permanent Root
2016-12-16 06:02:54 ZTE Z815 Z815V1.2.13 6.0.1 msm8909 Permanent Root
(End excerpt)
SRSRoot claims to be able to root this device, I've not heard of this root method before. You are free to try it at your own risk, (To either your PC or phone), or wait patiently for another method to be discovered. I myself will wait for a root method that (hopefully) does not require a program or APK that installs additional bloat onto my device, since the goal is to uninstall all the crap I don't want to begin with. In the mean time, I will continue to try and pester ZTE and T-Mobile to unlock our bootloaders, though I highly doubt I will get anything more 'intelligent' than the T-Mobile rep recommending me to get autoroot tools.
Dan