I think the club have tried to be clever here. Which is confusing people.
The way I read it, the cross bar is the GA+ bar. The location and the capacity adds up, this we know to date. It also ties in with the GA+ seat location and numbers.
I think the club have tried to 'lessen the blow of this publicly', by claiming the seats that need relocated are for the City Hall, rather than Cross Bar, because that sounds more pallatable. And because the city hall straddles the cross bar, technically, it is not 'wrong'. But in emails to those affected, it is seemingly the same seats and location.
In reality, there hasn't been any change, it is just how it is presented causing confusion. That's how I read it, at this point at least, I note I could be wrong.