From my previous story:
Looking at all the various links, it's clear that Skype for Windows Phone 8.1 is still supported at the moment, and you'll be able to continue to update it to the current version on a freshly reset Windows Phone 8.1 device, but you shouldn't expect the older platform to be compatible with everything going forwards after October. Newer versions of Skype will be through the new entry in the Store, currently listed as Skype Preview, a UWP for Windows 10 and Windows 10 Mobile.
Having used Skype Preview, I'm not sure that I'd call it light, fast or responsive, but hey, it's still effectively in beta, so let's give it a chance.
...Commentators online have tried to point out that this move 'leaves behind' 80% of the Windows mobile userbase, but this is twisting the stats. If you look at Windows mobile users who actually USE Skype (i.e. the enthusiasts, the tech-literate) then the majority of these are now on phones from within the last three years, meaning that they can upgrade all the way to Redstone and use the Skype UWP app.
We now have a little more information on compatibility and timescales. Here's the quote from the Skype support pages:
While support will no longer be available from October 2016, the Skype app on Windows Phone 8 and Windows Phone 8.1 will continue to work (possibly with some limitations) until early 2017, when we finish moving Skype calling to the cloud (see Skype blog).
Which is about as expected. And returning to my theme above, anyone with a 2012/2013 Windows Phone 8.1-only phone (i.e. can't be upgraded to Windows 10 Mobile and UWP compatibility) can't really complain that one of the Internet services on the phone stops working 4-5 years later. In the mobile world, that's an eternity. And 99% of those Windows mobile users who use Skype day to day will definitely be on a UWP-capable device by 'early 2017'.
In short, this is a non-issue, though I'd still like to see drastic performance improvements from the Skype UWP. Come on guys rip out all those debug routines!