As announced before, Microsoft is planning to stop the support for Skype services on the older devices such as Windows Phone, Windows RT and the messaging apps of Windows 10 mobile, TV etc. This is because of the previously announced decision to move its entire platform from P2P services to a cloud-based operation.
Now, if you open Skype web app or any other platform, you will see a notice regarding this. That means you won’t be able to access older Skype versions. Don’t worry, you will still be able to use Skype services on your new devices including Windows 10 Mobile and PCs. These changes are only appolicable for the older devices.