If you compare this to previous IMO this way it is clearer.

And yes, it needs to be send whenever data changes. As writes of url/title are initiated from declarativewebcontainer (it calls updateTitle and updateUrl) so when change comes back from database this signal is not emitted as nothing has "really" changed (local data is updated before data is written to database).

I can rename activeTabChanged to activeTabDataChanged if  you like it more.