Money in the Bank No Longer Part of WWE’s Big Four PPV List

For a very long time now, WWE’s big four when it comes to PPVs are Wrestlemania, Royal Rumble, Summerslam and Survivor Series. But for the past few years, the Money in the Bank PPV has constantly been improving, changing and evolving as part of WWE’s Big Four PPVs, replacing Survivor Series. 
However, Money in the Bank has now become exclusive to a single brand show PPV with Smackdown Live. Technically, Smackdown Live is the weaker show and a weaker drawing brand. As things were before, Survivor Series is now back to the #4 position especially since it is part of a weekend which includes a huge NXT PPV before it.
Source: Wrestling Observer Newsletter