I had some specific question about academics and being challenged. She said if you are accepted you can get into more specifics then.
The private school my son goes to really courted us and bent over backwards to answer my questions (in striking contrast to our public school, which clearly wanted us to just go away), so this seems odd to me, but how specific were your questions? I guess if you were asking specifically how they would accommodate your son, I can see why they might be hesitant to promise anything without first assessing him.
Do they have an open house you can attend? That was a good way for us to meet and talk to the director of the school and the actual teachers our son would have. It was far more useful than talking to the admissions person alone.