We emailed the ACC Security head to ask what policies were in place for the GA ticket holders during this leg's shows... This is what they had to say:
While some of the specifics of the GA policy are still to be finalized by the tour management, and is thus subject to change, the general admission line for all 4 U2 shows will form on the sidewalk on Bay St (east side of the building) starting at Gate 2 on the morning of the show. The line for general admission will be conducted on a first-come, first-served basis. No placeholder wristbands will be issued to allow ticketholders to leave for the day and return prior to the show, and ticketholders will not be able to hold places in line for ticketholders arriving later. Wristbands will be given out once the ticketholder enters the building - these wristbands are merely identifiers to clearly show which fans are permitted in the GA area. Unfortunately, information regarding how access to the inner circle of the stage will be conducted, has yet to be communicated to us by the tour management.