Wow! I am really sorry to hear about this, and I am sure that a number of orchid growers/vendors are as well. Many growers/vendors wait all year for this show to get out of the red. This may have devastating results for some of them...
In the past, I work for quite a few growers that came to New York from out of town. I worked at both the Winter Garden and Rockerfeller Center. As for the Winter Garden...it will never work. The vendors were set up (and sold orchids) on the bridge from the World Trade Center to the World Financial Center, Winter Garden. Most of the foot traffic (people) that came through the bridge area were people going from one building to the other, and mostly to commute, using the bridge to get to the subways under the WTC. During the weekend we had a number of buses that came in from other orchid societies in the surrounding areas. Also, orchid growers the were willing to spend big buck on parking, and those who were able to find Battery Park by train. As beautiful as the atrium (Winter Garden) is/was, because of its location now that the WTC is gone, the vendors would starve. On the other hand, the vendors loved Rockerfeller Center. It was located right in the middle of Manhattan, with almost every train in the area. Also, the foot traffic was amazing. The vendor did really well. I am sure that what is going on now has to do with logistics and affordability (since RFC wanted $20,000.00 to put a tent up last year, I am sure that the cost of having the show there has skyrocketed).
Regarding the Brooklyn Botanical Gardens... What I remember is that Dave Horak was, and maybe still is the president of Greater New York Orchid Society. Also, Dave works at the BBG as the curator of their orchid collection. So all of this information makes sense to me. As for the show being held at this location...sounds great to me. The BBG is a beautiful place. The vendors may need to sell their orchids from a tent (I am not sure what other areas are available); however, it should be an wonderful experience. I am sure that it would be more affordable to all who needs to vend there, to exhibit, and it is accessible to trains, etc. I am looking forward to the next show, if indeed it does take place there.