From what I hear the Lead Architect of Teams used to work on Lync. So I can easily agree that Teams is a child of Lync. Some things are improved though I hear a lot of people having issues with Teams sadly.
Teams is supposed to be the replacement. It's kind of trash as an instant messenger client, for entirely interface-related reasons - they built it in Electron, so it is difficult to pop out separate windows for individual chats, so one is stuck with tabbed soup.
Although it's probably the best voip and video conferencing software they have put out.
Although it's probably the best voip and video conferencing software they have put out.