Invasions are indeed over, but plenty of trig and edencom related content remains.
The Abyss- Instanced PvE content. Plenty of players are opposed to the instanced nature, but lots of people like doing it. There are no shortage of guides on youtube available for those that are interested. Maybe start with Aceface’s channel.
Pochven is a new region cobbled together from existing solar systems (which ones were decided in invasions chapter 3). There is a small community living there, but it has largely been ignored by the wider player base. Personally, it sounds like the region is halfed baked, but you should probably talk to the people who actually live there if you want to know more.
Trigs and Edencom forces can also be found in various HS and LS systems. Edencom forces are neutral by default, but you can get on friendly terms with both factions rather easily. This is highly recommended, as it makes transversing new eden much easier, and prevent any surprise losses to trig ambushes.