Yes, you have a chance to explore the stage after the show or get a signed poster if you buy the album, pretty much the same as last year's AT
And if you don't win anything, you get a card. The text in red just says that even though you get to walk on the stage, you won't meet Ayu.
Don't know what details are though, I'm not good at Japanese. I think it counts for both pre-order and if you buy the album at the venue after it's released? And maybe you could pre-order it at the venue even if you're a foreigner, but you'd need to be able to write the whole tenso address in Japanese.