But Slack also wanted to "sneak Electron into the (WinRT) clubhouse," as the blog post explains. Electron is an open source framework from GitHub that is based on the Node.js runtime and Chromium web browser.
Slack contributed to and used the electron-windows-store tool that is designed to turn electron Apps into Windows AppX packages. This tool has been available since last year, around the time Microsoft enabled Win32 PC apps to be available through the Store as part of its Windows 10 Anniversary Update.
The Slack blog post reiterated the oft-stated reasons developers might want to bring their apps to the Windows Store: Better application discovery; one-click installations; "no files or registry items left behind"; and the ability to interact directly with hardware, lock screens, payments, notifications, and Cortana.
Sounds good on virtual paper, but I'm curious how many apps are in the Windows Store. It's been ages since Microsoft released an updated number. Knowing the impact of the bridges on total number of apps in the Store would be interesting, too.
Microsoft hasn't had much to say around its evangelization of the Windows Store and Universal Windows Platform apps lately.