Top brass in Yahoo Labs have left, and the company has moved to kill off digital magazines and other products in the past few months. In February Yahoo announced that it was laying off 15 percent of employees. The announcement comes as Yahoo reviews strategic options, including a reverse spin of certain properties. The change affects the legacy Messenger clients on Windows, Mac, Android, and iOS. We intend to continue our focused efforts on the new Messenger, with a goal of delivering the best experience to our users While today we provide basic interoperation between the legacy product and the new Messenger, we encourage all of our users to complete their transition to the new Yahoo Messenger as we will no longer support the legacy platform as of August 5, 2016. This complete revamp brings users an incredibly fast, beautiful and smart way to send - and unsend - messages, photos and animated GIFs in 1:1 and group conversations. In December of 2015, we announced a brand new Yahoo Messenger for mobile, the Web and in Yahoo Mail on the desktop, built on a new modern platform.

Here’s how Yahoo explains the move in a blog post:

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