I was there in 2015. SAP wouldn't allow people to line up in front of the venue until 8am, but a group had formed next to the arena before 8am and they numbered people's hands and then proceeded to walk over to the venue at 7:55am. I didn't know there was an "off premises pre-lineup," so i got there for 8am. Pretty sure my number was under 100.
I tried to attach the screenshot of the procedure set up for Justin Timberlake on 4/24-25, but the file is too large. It states lineup begins at 9am, wristbands will be given out at 9:15am. Once the GA ticketholder has their wristband, they may remain in line or leave the area, but must report back to their sequential place by 5pm.
Perhaps a foreshadowing of what will be in place for U2 in May...