Even though the event would be held during the summer, The Wrestling Observer reports that there was some talk of trying to host the event at MetLife Stadium, the site of WrestleMania 29.
Regarding Madison Square Garden, it's likely too expensive to run a major show there these days, compared to other arenas in the same area.
Source: Wrestling Observer Newsletter
Subscribe to The Wrestling Observer by clicking here. Each issue has coverage and analysis of all the major news, plus history pieces. New subscribers can also receive free classic issues.