I guess I'll contribute a bit beyond extracting stuff from the mission file

("Where do the Shivans come from? Who made them?"
("incursion event and worldline intersect logged at present minus 5 x 10 ^ 9 years"
Pretty simple, but too vague to tell if this is a date for when the dawn war happened, when GD was unleashed or simply as a means to control the races living at the time to make sure diversity was preserved.
("panreal exostosis and enmeshment IMMEDIATE across volumes and layers$semicolon perimeter HOT$semicolon contextualization PARTIAL"
The vishnans refer to the 13th battlegroup as returning to their home layer, so im going to asume that layers = paralel universe. Volume could refer to the physical universe itself.
Perimeter hot? as in this universe just recently (in astronomical terms) appeard and its very hot and chaotic or most likely they appeared in the middle of a warzone basically.
Contextualization partial.. not sure on this one beyond maybe assesing the races currently alive or in conflict, the state of the universe itself, its galaxies, jump node configuration etc.
("totipotent threat response agency prioritized, goal hierarchy heuristic partial slave$semicolon cognition HARDENED"
This one is what i based my above argument of being dropped in a warzone on.
Threat response is prioritized, why do this if there is no threat? although it is arguable this is in the very nature of the shivans as some sort of default setting.
Goal hierarchy herustic partial slave, really unsure what the hell this means, mostly because all we really know about the shivans is they are predators and at some point (supposedly later than when they first interescted our reality) they started utilizing the terminal protocol as a sort rulebook. So what was their purpose before that? under the description of predator they would have wiped out the entire universe, and maybe that is exactly what they did. Still I'm not sure on it.
cognition HARDENED: I guess this could imply that they went in some sort of mode that increases their combat readiness over what is later on described as a basal state. Or maybe the opposite, keeping things simple and clear to deal with what we normally accept GD as... some sort of cognition virus that makes you go mad and contemplate the odds of seeing a large amount of armless and legless corpses on a hangar deck.
("The Shivans are eternal. They were not made. They were calculated."
I think this basically means the shivans didn't "enter" our universe from a subspace node or some sort of gate. They simply appeared as a calculated response to something by the greater organism, reality itself.
If the vishnan are said to utilize the universe to perform calculation why could reality itself not be a living thing that has the same perspective we do of our our own cells and immune system.
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I'll continue at some point I guess