As was noted earlier, WWE has moved the Money In The Bank show from Allegiant Stadium to the much smaller MGM Grand Arena, thus canceling out hopes to turn Money In The Bank into one of the "big 5" shows as far as ticket sales.
CM Punk took to Twitter to mock WWE's decision by including a photo of Sgt. Slaughter and Hulk Hogan from WrestleMania VII advertising. Punk is referring to WWE moving Mania VII from the LA Coliseum to the smaller Los Angeles Sports Arena. Ticket sales were nowhere near close to selling out and it was reported at the time in the Wrestling Observer Newsletter that WWE was claiming that they moved to a different building because of bomb threats due to the heated angle between Slaughter and Hogan. The Observer noted that the ticket sales were actually to blame. Low ticket sales are likely to blame in this case as well.
The latest update on Money In The Bank ticket sales (via WrestleTix's Patreon) is that WWE had Allegiant Stadium set up for 27,114 tickets. As of May 20, they had sold just 19,594 tickets. Allegiant Stadium can hold around 65,000 fans for NFL games and likely more than that for a wrestling event.