1. They are hurt bad since last encounter, so they are careful with contacts with humanity.
2. If they are in the bubble, they have friends that are protecting them.
3. If they are in the pleiadies they are hiding well with technology we can not yet detect properly.
4. The incident with destroyed federal ships are not saying anything really. Accidental skirmish, nothing to worry about.
5. If Thargoids do show up, they are to be considered fully armed, ready to counter human kind and have learned how to defeat us if we start to misbehave.
6. If we go to war with the Thargoids AGAIN, which I think is a BIG mistake for both parties, then we can assume that the first thing that will happen is a bubble wide outbreak situation with catastrophic economical complications.
7. Even if we deal with the outbreaks ( CG's ), the Thargoids will have spread like fungal mycel through the entire bubble, occupying every key system we needed to defend our selves properly, and we will be under Thargoid rule.
8. If we do get a peaceful communication with the Thargoids ( Thargoid rather, cause the hive mentality of the higher org ), then we can assume there will be very sparse trading and mission interaction due to the suspicious actions of/by our Potters.
9. If the Thargoid keep hidden, then we can assume they are NOT strong enough to take us on in war and therefore we are safe. We can keep the peace and work on improving relations so we can suck all their secrets out of them in a friendly way.
10. When we start 2.4, there will most likely be a hidden, locked feature, where we can start as a Thargoid commander and fly Thargoid ships and do Thargoid side things. This is speculative, but very likely because Sir(not yet? ok..) Braben and FD are masters of content.