HMD Global has not revealed any information about the unreleased devices. It has achieved a bit of success and now every smartphone OEM is looking forward to released X variant of their own.
We have seen a number of leaks regarding some unreleased devices from HMD Global. And since nearly all numbers below ten have been used up, Nokia perhaps wants to use the "ten" but instead of calling it Nokia 10, why not Nokia X. We're only guessing but there's also a possibility it will have the same fate as the Nokia 3310 which was a reboot of the model from the last decade.
Or it is also possible that HMD Global may re-launch the Nokia X line this time with stock Android and better specifications.
According to NokiaPowerUser, the Nokia 3 smartphones in India have started receiving the stable version of Android 8.0 Oreo. The lineup got discontinued once Microsoft acquired the Nokia brand.