They'll be going on the grill.
So long as you are planning to then cook your vegetables to 165ºF, I don't think there would be any food-safety issues with that.
I wouldn't suggest it. As PhillipBrandon says, they'll need to be cooked to the same temperature as the chicken. At that point, I think they may be overcooked. Marinade them and handle them separately, and you'll have no worries.