systemsettings5 correctly displays settings for KF5 applications, so it's just a question
of more KF5 packages making their way into the archive. You can verify this by installing
bluedevil (currently 4:5.3.2-1 in unstable) : a bluetooth icon appears.
This seems reasonable, but I don't understand what the plan is here. It seems like it was premature to upgrade systemsettings to the v5 version before the rest of the system was ready to handle it. I ran apt-get upgrade and my whole settings system broke. Was this really the intended behavior?
-Matt