it may not be the same, but when i went to see green day at MK bowl, and its a massive outdoor grass bowl so there was no seating, and there was a golden circle at the front so it basically was a free for all when they opened the gates - minus the golden circle which you needed a wristband for. i cant see them being able to put lots of seating in jsut for this concert. so my guess is that yes it will be all standing, as it is with all other gigs there. i just had a quick look on the bowls website and it states that it is an all standing venue, in the take that gig section .
http://www.thenationalbowl.net/
try asking other people on the message boards your queries if the website isnt any help, i found the people on the message boards much more useful than the site when i was going to see greenday.
hope this helps.