When my great grandma was born, we didn't have flight, radar, lasers, radio, etc... Why would we think that a civilization capable of building massive space structures would be communicating in such a slow and imprecise way. The idea that we've discovered all there is to know about communication over vast distances is hubris.

We can't see anything because we have not yet discovered what we're looking for.

Well, if it's actually a Dyson swarm in the making, we'll find out, watching the star go gradually dark during the next few hundred (or thousand?) years..

Is there any reason to expect such narrowband signals, or are they the only kind of signals they could hope to detect?

Correction: "No signal that we use Detected from KIC 8462852"

And ? Nobody with good physical understanding uses Hertz EM waves for communication except emergency broadcasts if he is clever. Assumptions over assumptions and not looking outside the box, this is what SETI does and that's why they are not seeing anything of interest.

It would make no sense if a Type 2 Civilization this close to earth did nothing to us.

Is there any hope of discovering historical observations of this star ?

>1480 light years away

One point consistently glossed over is the fact that if you believe nothing can exceed the speed of light then even if we find intelligent life we will never communicate in any meaningful sense of the word. It would be more like mutual observation. Are there any sci-fi works that acknowledge this depressing reality and somehow manage to make a workable story?

God will talk using just about any random process as an oracle. You have to do an offering by talking to Hi for 5 minute being witty and charming, praise, perhaps writing a hymn.