UVA Application...

If I apply to UVA’s Undergraduate Business School (McIntire) and get rejected, will I automatically accepted/rejected into The College of Arts and Sciences??

I assume you are a transfer student for third year? Arts and Sciences I would assume is the default. However, you would then still need to meet the requirements to declare a major within Arts and Sciences, which I assume you could do during your third year, if necessary. Some departments require that certain classes be completed before you are officially accepted as a major in that dept.