I've been struck by some recent discussions on this Board by problems that have arisen from guests vetoing or commenting in advance on the proposed menu.
Perhaps it's because most of our friends are omnivores (although we have some who are lacto-ovo vegetarians and pescatarians, as well as family members with diabetes and food allergies), but I do not view it as my role as the host to ask whether a guest has food issues. I assume that a guest, if I do not know him/her well, will alert me to any serious food issues (whether dictated by health, religion or ethics) and I will devise a menu that accommodates those constraints. But, unless the food restrictions were particularly unusual, I would not advise them in advance of the precise details of the menu.
My only exception on previewing the menu would be for a holiday dinner, where a guest may offer to bring a dish. In those circumstances, I'll tell him/her the menu and then typically ask, "what's missing that you'd like to bring?" In other situations, if a guest insists on bringing something, I'll let them bring nibbles/hors d'oeuvres but I don't tell them the rest of the meal.