I don’t see any loss for you to Triglavians. The answer to your question depends in which system you got killed.
There are trig system like Nonni and many others. And there are also systems that might have trig spawns because there is a wh nearby that leads to one of the trig controlled systems.
Both do not always have trigs on gates, one will always have trigs (beause a trig system) the other will only have trig is there is a wh to their space.
And no… the ones that have turned to 0.0 is done. That event has ended.
I found a really helpful guide to getting standings with them. Doesn’t take very long to achieve, not counting figuring it out it took me some 30 minutes in total.
You’re not neutral to them, as evidenced by them obliterating you and your ship.
Don’t assume that no standing is the same as a ‘true neutral’ standing where they don’t care about you at all. By default they kill you, unless you gain positive standing with them.
Currently they can appear in any System that has wormhole connections.
If a wormhole to Triglavian Space (a 27 System wide area under their control named Pochven) opens up in a System the Trigs will come through, gate camp, station camp and generally be very annoying. This can happen by surprise with no warning and no intel reports in advance. You can literally jump into a ‘perfectly safe’ High Sec System that didn’t have Trigs in it earlier and find 20 of them waiting for you on the other side of the gate.
They usually hang around until the wormhole closes again, or until destroyed by players.
This is now just an unfortunate hazard of High Sec life. Sometimes you can see them if they are on your exit gate, or see dozens of wrecks, or hear the screams of dead pilots in Local chat. Watch out for these things as you fly and you may just avoid them.