WhatsApp and Microsoft are planning a 'real' Windows app
According to reports, WhatsApp is working with Microsoft to develop a proper Windows app. While the current WhatsApp for Windows Phone is updated regularly and works fine, it isn't a Universal Windows Platform (UWP) app and can't run across all Windows 10 platforms. It is based on Silverlight, which is an old 2014 technology, and is not supported by all Windows devices used today.
Porting WhatsApp from Silverlight to UWP
According to concept images from a designer working on the project, the new app will be UWP-based and run across different Windows 10 devices universally. It will have native Windows design elements like acrylic transparency. The project description stated, "We want to bring WhatsApp to Windows 10 desktop and integrate unique Windows 10 features like Ink and Fluent Design."
Not to be confused with WhatsApp Web
To be clear, WhatsApp already has a desktop app but that is just a web version of its core mobile offering. WhatsApp Web lacks several crucial features like voice and video calling. According to reports, the new UWP app shows call buttons in concept images, suggesting it will have telephony capabilities. This will make it a standalone native client for Windows 10 devices.
Microsoft's upcoming Andromeda smartphone will not be Silverlight-compliant
Reports also suggest that Microsoft's much-rumored foldable Surface smartphone, codenamed Andromeda, will feature the new WhatsApp for Windows. This is hinted at by several concept images that are in the tall aspect ratio of a phone. The phone can be released this year itself.