Component not added to model?

Ok, so I have a component that contains a data class. It looks something like this:

 [Serializable]
 public DataClass
 {
     public string someData = "";
     public DataClass() {}
 }
 
 public class MyDataComponent : MonoBehaviour
 {
     public DataClass myData = new DataClass();
 
     public void Update() {}
 }

Now, I'm trying to add this component in the asset processor as certain models get imported.

 void OnPostProcessModel(GameObject go)
 {
     MyDataComponent foo = go.GetComponent<MyDataComponent>();
     if (foo == null)
     {
         foo = go.AddComponent<MyDataComponent>();
     }
 
     // assume we init foo with some data
 }
 
 public static void OnPostprocessAllAssets(string[] importedAssets, ...)
 {
     // assume we get the same asset as above
     string modelPath = importedAssets[0];

     GameObject model = (GameObject)PrefabUtility.InstantiatePrefab(AssetDatabase.LoadAssetAtPath(modelPath, typeof(GameObject)));
 
     MyDataComponent foo = model.GetComponent<MyDataComponent>();
 
     if (foo == null)
     {
         // FOO IS ALWAYS NULL
     }
 }

This seemed to work for me when the contents of DataClass were directly in MyDataComponent, but now that I've encapsulated them, suddenly it doesn't work again.

I can't figure out why the component returns null now when it was valid before.

Thoughts?