If the CZ is on-time, or even just a few minutes late, you'll have time to grab something in the food court. There's a McDonald's that has relatively quick service even in the middle of a workday rush, and there are some hot dog and pizza places as well. The longest I've ever waited for food is about ten minutes.
You can bring your food on the train, so even if you don't have time to sit and eat, you can still pick something up. I used to get a burrito bowl from Burrito Beach and eat that on the Wolverine.
The Blue Water has a cafe car, so if the CZ is super delayed and you have to dash to the Blue Water, you can have a sandwich and whatnot on the way to Port Huron.