Unfortunately, nothing happened in the following months, and both smartphones remained stuck on Android 6.0 Marshmallow. What's worse is that there's never going to be any software changes, at least when it comes to the OnePlus 2.
OnePlus has just confirmed that it will not release new major updates to the OnePlus 2 going forward. Basically, this means that an Android 7.0 Nougat update will never arrive for the OnePlus 2.
Although OnePlus has yet to make any official statements regarding the OnePlus X, it would be safe to assume the worse.