My question to you is who is calling for the cap? Is it the individual orginazations or the administration of the college? If it is the administration of the college than I suggest that you confer with other colleges or universities that have had a similar expierence, either on the national or local level. This way you get varried opinions and may choose the best course of action.
I will warn you that if an individual orginazation calls for the cap their motives will be questioned, not only by the disgruntled students left out in the cold , but sometimes by the administration as well.
I am sure that your motives are sincere, but just be careful- the last thing you need people trash talking your sorority.

Fraternally,
A concerned sister