I like the "Thargoid mystery build-up phase" in game lore. Basically there are references and hints all over the bubble, and then, finally, a proof of their existence. It lost some of its momentum when Thargoids started to appear in signal sources. It was a new chapter though, Salome saw them, major political figures could no longer deny their existence, INRA was revealed. Black Flight had lost their mission of obfuscating history.
Those ships, perhaps destroyed in order to keep information of Thargoids secret, could be an in-game reference to Mic Turners past operations in that area, and whoever followed in his footsteps, Commander Jameson (assuming there was a league of reparation then), Thunderchild team, or something else. Independent pilots witnessed all sorts of weird things out there, but it was dangerous information to have.
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Alliance of course kept up the tradition of xeno-research, as seen in California Nebula. Sirius always knew, and had an extensive colonization project, and quite likely, funded planetary mining in the area, before "Sirius Mining Merope". Pleiades was becoming the hotspot for alien activity early on, and both Federation and Empire happened to have a great interest in this area, nearly plunging themselves into a war for it. They all think its worth the effort. It's all because our technology is based on alien technology. It was an arms race, and reason for the secret influx for alien objects transported into the bubble. Black Flight was the first in business. "Exodus" refers to Thargoids, not humans, and was intended to reverse it. Mycoid virus destroyed their network, starmap. Artifact is a polyp.
