According to The Wrestling Observer Newsletter, WWE was not originally planning on having a WarGames Match at the upcoming NXT TakeOver event.

WWE's original plan was to have Drew McIntyre vs. Adam Cole for the NXT Championship as the main event, with SAnitY vs. Bobby Fish & Kyle O'Reilly for the NXT Tag Team Championships as the co-main event.

It's unclear when exactly the idea to bring back WarGames came up but it may have been a last-minute decision.