No idea.
Remember this is Angus’ first US tour in 9 years and realistically it’s the last one. This is I believe the longest they havevever gone without playing here….they may be banking (pun intended) on demand being there..
Also if you play a stadium you can theoretically have an average ticket price that’s lower meaning more can afford to come. Yes they will be further away but they will see AC/DC. At an arena the lowest ticket prices for a band like AC/DC would be, what? $99.99? Funny to think when I saw them in 2008 I had a second row center ticket I got for $99 for the tour opener in Wilkes barre. I did have to join the fanclub to get the ticket though.
And while the rest of the world is different they are a stadium band elsewhere so there is cost savings I guess in not having to retool the setup for arenas?