I have the BX2200 with a RB1560 blade. I looked at the manual and it appears that the RB 1572 uses the same frame. With that said it seems to me that there would be adequate clearance for a full 360 degree spin of the blade. There is more than the additional 6 inches needed (the blade is 12 inches bigger but only 6 inches matter in this case) to clear any obstructions. (Assuming you do not need to offset the blade and it is centered on the frame.)
BTW, wouldn't the dealer let you try it or understand that if you can't rotate it than you would return it, or is the dealer located very far away? The price in very good IMO and I would take the savings and purchase the optional skid shoes. Without draft control on the BX it (the shoes) make it very easy to set the needed height for leveling dirt or moving snow, etc.. I have them and also have the gauge wheels for the LP landscape rake that uses the same frame as the blade.
Hope this helps.
