As a writer and worldbuilder I've recently been really fascinated and intrigued with the Dark Side ending of TFU 1 and the implications of certain events that unfold (since the Lord Starkiller/Dark Side timeline has a lot of untold stories and events outside of the Tatooine & Hoth missions, like what comes before and after etc.), one of which being the formation of the Rebel Alliance in this timeline
The Light Side ending follows Leia and the senators establishing the Rebel Alliance using Galen Marek's family insignia, only possible with Marek sacrificing himself during his battle against the Emperor so the senators can escape. In the Dark Side ending, the captured senators are killed and Marek becomes the Emperor's new apprentice after killing Vader, thus the Alliance is never established.
Except it does and uses the exact same name and insignia?? What's more curious is that the events of the Dark Side missions closely follow the events of the OT movies despite everything being drastically different leading up to these moments. The senators die but the Alliance is still formed (Bail Organa does mention "Our deaths will only rally others" before Starkiller fights Vader, and they do die in the Dark Side ending but it's still intriguing how it happened compared to Light Side), Lord Starkiller kills Obi-Wan and (supposedly) tracks Luke's crew but the Death Star still blows up, the Rebels and Empire are duking it out on Hoth, etc.
Overall it's a really unique setting and scenario to think about imo, one that didn't even cross my mind when I was too focused destroying everything and throwing the OT cast around like ragdolls when I played this as a kid lmao
Honestly it'd be pretty fun to write and theorize about, what do you think?
¯\_(ツ)_/¯