It’s been a while since ZTE has released an update for their Axon 7, but it looks like they’re still supporting the device with both security updates and new features. The Android version number is still 7.1.1, but 7.1.2 was mostly for Pixel phones, and it would be a little eager to expect Android 8.0. While all cellphone manufacturers should push security updates as quick as possible, because particularly nasty issues can be exploited within hours of a patch being publicly available, not months, at least they are still doing them at all.
The ZTE Axon 7 was released a little over a year ago.
The most noticeable update is the multi-user support, which adds a colorful icon to your lock screen. When you click it, you’re able to choose the user to login as, create a new one, or create a guest account. I have noticed that the phone is also significantly more responsive, especially when rotating the display, but they might have just shortened the animation. Either way, it feels a lot faster, which is good, regardless of where that performance comes from.
If you're considering a phone from ZTE, then this should give clues about their intended update schedule. It's not Google-level, but it's at least a year, if the Axon 7 is any indication.