Steps to reproduce:
1. Open the original project "TestSpriteTextureMissing.zip"
2. Navigate to Project -> Assets -> Scenes and open SampleScene
3. In the top menu bar select "Test" and "BuildAssetBundle"
4. Enter Play mode
--Notice the sprite on the left lost its reference to the texture

Expected results: 2D Sprite Prefab Loaded from an AssetBundle is Instantiated with all its references after AssetBundle is unloaded
Actual results: 2D Sprite Prefab Loaded from an AssetBundle loses its Texture reference when it is Instantiated after AssetBundle is unloaded

Reproducible with: 2017.4.28f1, 2018.4.1f1, 2019.1.4f1, 2019.2.0b4, 2019.3.0a2

Note: Versions 2019.3.0a3 and above do not load the Assets from the AssetBundle, probably because of new Editor