they didn't leave MSG high and dry in any way. the garden is ASTRONOMICALLY expensive to rent out and even more so if you plan on broadcasting anything from that building. thats why they only do house shows there now.
I think they should have ran it anyway for the prestige and legacy value. Especially if they aren't going to have a Brooklyn Takeover this year since Summerslam is in Toronto. In fact, had they booked it one of the nights, I'm sure NJ/ROH wouldn't have been able to run it at all and the whole topic of discussion would have been written off before it could happen.