Yes, that’s correct, trying to remove the voicecall-ui app will break your system. Also, reinstalling can cause problems, so that is disallowed generally.
devel-su pkcon remove voicecall-ui-jolla
would be the command to remove an app, but in this case, you are disallowed. In the same way that
devel-su pkcon install voicecall-ui-jolla
would be apt to install, but this often yields the same message we see upon removal.
Sounds to me like the OS update botched something. If it were me, I’d do the update again…