I commented an hour ago about what I thought happened in Champion City page, and I thought I'll share it here too.
Here's the comment:
Eric Stirpe mentions in this post that originally there will have been a shot of Romeo (the admin) "teleporting all the Champion City residents into Beacontown shortly after blowing the city up."
My first thought is that this would obviously be the most likely canon as to what happened to the residents in Champion City. However, Eric Stirpe also mentions that "Romeo sparing all the people isn’t canon. I’m a little conflicted about that, if I’m honest." which is very understandable. Why would Romeo bother to save the residents inside of Champion City where he wanted to just point out something?
Here, I will give my reason as to why Romeo will teleport all the residents of Champion City:
First of all, why did Romeo faked being Jesse? That's because he wants to be like Jesse, a hero who everyone loves.
Now, the reason he destroyed Champion City is to give an example as to what will happen to the other two cities if they didnt do "more agreeing" with him. So, he would also teleport all the Champion City residents calling himself "a hero" for saving their lives, it will fit his sense of being "the hero that everyone loves".
Here's what it would look like in dialogue (Here's a video on the scene):
It will start after Stella says "My... No." and kneeling near the admin (at 1:41).
Olivia: "A-all of those peop-"
Romeo: Summons all the Champion residents in Beacontown.
A quick scene shows all the residents outside the entrance of Beacontown.
Romeo: "See how good I am? I saved all of these lives, I am a hero!"
Romeo: "And we have a lot more people to see the show, isn't that the best? Hahaha." (Extra)
Then it cuts to the other characters that are hiding.