Just seen they're from Wikipedia. They're cited to the Billboard Boxscore, but I the Sats do not appear in it at all for the last few weeks.
Furthermore, the maximum capacity for Cardiff is 7,530 - and that's standing.
Further still, it's not called even called Cardiff International Arena, it's the Motorpoint Arena, and that name update has been reflected in the Boxscore charts for ages (at least since Katy Perry back in April)
So, definitely fake.