Currently models built or saved in ArcGIS Pro aren't visible in ArcGIS Desktop. Models built in Model Builder, regardless of which software platform, should be visible and executable in ArcGIS Pro and ArcGIS Desktop. If there is some functionality that prevents it from being executed then it should have a red X on it that signifies that it can't be run (e.g. a model built in 10.3.1 viewed in 10.2.2 or a model using an extension that isn't licensed).
Not in Current Product Plan