You're right; I had missed that part of the conversation.
In my state, in theory, the funding inequities have been fixed. Districts aren't strictly dependent on their local tax base. Meanwhile, charter schools are supposed to provide districts with competition, which has happened, but that has pluses and minuses. A lot still depends on transportation: Many parents will default to the school that runs a bus in the neighborhood. And there is still de facto segregation because that's how some parts of town are organized. So then comes the issue of community integration which I don't want to see forced on people, but it could be incentivized.
The posh high school ended up with extra capacity and found it was worth their while to run buses outside the district to bring in a few kids from less-exclusive parts of town. The charter system allows for some pretty good schools in pretty rundown neighborhoods. Bottom line, motivated parents can sometimes find options better than their default neighborhood school, but what does that do to neighborhood schools? They're supposed to "compete," somehow, but having a bunch of underfunded entities trying to claw resources away from each other isn't pretty, either.