Comment # 11 on bug 1221405 from Aaron Puchert

(In reply to Fabian Vogt from comment #9)
> For Plasma units it would probably make sense to just remove the %preun
> scripts completely, but I'm not sure whether that's correct for Plasma or in
> general.

For actual services, stopping on removal make sense to me, even if there is a
package rename. I think the problem here is that these are not real services,
they are parts of a session and KDE abuses the service mechanism, presumably to
get separate systemd cgroups for these processes. (Though one could argue that
the issue is with systemd not allowing to subdivide a session scope.)

So these "services" should probably not be stopped, just like an update of
Plasma shouldn't restart them.