Understandable choice, given that Skype is pretty much redundant with Teams. Back in 2004-2005 Skype was really hyped because of free voice calls through the Internet, but few days later several other messaging apps incorporated that feature; Skype’s thunder was stolen. Also its inconsistent branding was a problem: there was Skype for Business that later became Lync, ultimately becoming Teams. Skype kind of became forgotten and obsolete.
It’s the other way around. Lync, formerly Office Communicator, became Skype for Business which became Teams, not to be confused with Teams, a distinct, non-interoperable product made by the same company. Skype for Business probably took some code from Skype but I’d bet it was mostly about branding and it never had that much in common with the real Skype.
Microsoft killed Skype in 2017 and replaced it with a different thing also called Skype.