Moreover, they have (had?) an entire multi-year roadmap planned around UWP, including the eventual release of a version of windows which was supposed to substantially reduce day-to-day reliance on Win32 for lower powered devices, codenamed Project Polaris [2], in an attempt to compete with Chromebook-like devices.
This is a massive destruction of confidence in the UWP platform. If Microsoft can't even release their marquee apps on it, why should anyone else feel confident in developing on the platform?
[1] https://www.theverge.com/2018/4/18/17252312/microsoft-office...
[2] https://www.windowscentral.com/understanding-windows-core-os...