Both of these devices arrived in 2016, but the company is still actively pushing updates for both phones, as you can see. (androidheadlines.com)
Android devices are known to have slow updates due to manufacturers and carriers taking time to add their own user interfaces on top of stock Android before pushing updates out to users. (ibtimes.com)
If a device has received Android 7.0 Nougat, it's very possible your carrier has not pushed the update through. (digitaltrends.com)