Project Astoria will not be in the next Windows Phone version.
“We’re committed to offering developers many options to bring their apps to the Windows Platform, including bridges available now for Web and iOS, and soon Win32. The Astoria bridge is not ready yet, but other tools offer great options for developers. For example, the iOS bridge enables developers to write a native Windows Universal app which calls UWP APIs directly from Objective-C, and to mix and match UWP and iOS concepts such as XAML and UIKit. Developers can write apps that run on all Windows 10 devices and take advantage of native Windows features easily. We’re grateful to the feedback from the development community and look forward to supporting them as they develop apps for Windows 10.”