Anyone still chugging along on these older versions will no longer receive the newest versions of Skype going forward. Unfortunately, this means that some users won't be able to utilize the Skype app to the fullest as time goes by.
The changes were outlined by Microsoft's corporate vice president of Skype and Skype for Business Gurdeep Pall, who was quick to admit that Skype has had its own issues in the past. He noted that "unforeseen issues" have indeed been a thorn in users' sides for some time, such as "messages not syncing across devices or delayed notifications."
Microsoft notes that the transition from P2P to cloud service of the last few years may be part of the problem, and with the transition still ongoing, Microsoft is hoping to wrap things up in the coming months.