I have all sorts of different versions of Skype in our environment. I have a WSUS server where Skype is selected under Products as for Classifications everything apart from Drivers, Feature Packs, Tools is selected.
Not a single Skype update is available on the clients, I have nothing to approve and naturally nothing gets updated. From which version of Skype is this supported are perhaps only Business versions supported? All other updates are available and get approved/installed without issue.
BTW I'm aware of the recent fiasco with the accidentaly deployed update even to machines without Skype, this did not affect us (no auto-approve here).