Sim City 4, been a long time since I played it, but still one of the best soundtracks.
Two of the best tracks in my opinion
https://www.youtube.com/watch?v=rCfimZEArAQ&
https://www.youtube.com/watch?v=Q8HW5agFwUY&
The Plane exploding has nothing to do with preventing the AI uprising which is Matsumoto's mission and also needlessly altering the timeline might cause unforeseen events. So Matsumoto attacked Vivy to prevent her from preventing the accident.
The whole theme of the anime so far is that AI are determined to complete their mission. Vivy promised the girl that she would sing on the main stage the next time she came to the Nialand. The girl has to be alive to see Vivy singing on the main stage so to complete her mission Vivy needed to stop the girl from dying.
So yes the girl on the plane is dead for good as per the original timeline. Vivy and the bear are not on good terms but Episode 3 takes place 15 years after Episode 2 so I guess the long wait helped?