Really "gluten-free" means that someone with severe celiac disease could eat there, and the acceptable levels of flour/gluten/whatever have to be very, very low. So low that you will probably need two separate food prep and storage areas. That doubles the space and staff and work requirements.
That being said, gluten-free reheated frozen food out of a bag is just a more expensive version of ordinary reheated frozen food out of a bag, so I don't think it would help these places very much.
That being said, gluten-free reheated frozen food out of a bag is just a more expensive version of ordinary reheated frozen food out of a bag, so I don't think it would help these places very much.