When we cruised in January I brought my little steamer and used it everyday! I had no idea they were not allowed! I just always bring mine when we travel. It was left out on the desk everyday, so our stateroom host must have seen it, as we were not hiding it, but he never said anything about it to us.
I just looked through the brochure and it states "For safety reasons, irons and steamers may be used in the laundry room only."
So to me, they are saying you may bring them, but they must be used in the laundry room. So next cruise, I will probably bring it again but use it in the laundry room this time.