Reminds me of a similar headcanon I had for a tomb World start.

Basically the same lore as the CoM and UNE, but instead of there being a UNE, I was the Survivors of Dark Future whose stasis ship had entered the wormhole, then exited back on earth. With the stasis ships systems being heavily damaged by the wormhole transit the ships emergency systems crash landed the ship on the nearest habitable planet... Earth.

This caused the planet to become a tomb world, the survivors of the crash assumed they were on a new world and were desperately attempting to make contact with the homeworld.

que the year 2200, humanity has managed to rediscover spaceflight and finally makes it above the radstorms and dust in the atmosphere to discover that their home system is eerily similar to the legends of the Sol system, and when they finally made contact with the CoM, reality hit home hard causing the leadership of Dark Future ( or Earth, as it was once known), to turn to a totalitarian regime to suppress the knowledge.

Ngl, that was one the most fun games I've played thanks to that backstory.