Regardless of their reasoning for the venue change, I like the new one they're going to. It's a outdoor soccer stadium which holds around 25,000 people. It's something I have been hoping WWE did more often for bigger events. Rumble is headed to a baseball stadium, WM are in football stadiums, and as excited as I am for Summerslam in Toronto, I think that should be held at a soccer(MLS) type stadium.
You still get that outdoor environment without needing over 50,000+ people attending.