The Prefab Instantiator and Prefab Instantiator Async components have been consolidated into a single new component known as the Prefab Chunk Streamer within SAM, which you will need to create using the new Deep Space Labs component creation menu.
You can add this component by selecting a game object and then selecting from the Top Menu Bar:
Component -> Deep Space Labs -> -> SAM -> Chunk Streamers -> Prefab Chunk Streamer
or by selecting a game object and using the Add Component menu via its inspector:
Component -> Deep Space Labs -> -> SAM -> Chunk Streamers -> Prefab Chunk Streamer
This setting has been removed, as the new Prefab Chunk Streamers works with async loading.
Remember, previously Cell Object Loaders were assigned to Primary Cell Object Sub Controllers. In the Streamable Assets Manager, the Chunk Streamer component is assigned to the World, either via the Default Chunk Streamer field found in the Overridable Settings window, via the Chunk Streamer field within the Grouping Overrides window of any World Grouping, or via the Chunk Streamer field of any LOD Override.
The Chunk Streamer class is now responsible for destroying/removing Asset Chunks from the scene, whereas in the Terrain Slicing & Dynamic Loading Kit this responsibility belonged to the Primary Cell Object Sub Controller.
As such, you will see some settings on the Chunk Streamer that were previously found on Primary Cell Object Sub Controllers, such as the (now renamed) Chunk Destroyer and Memory Freeing Strategy.
Each setting on the Prefab Chunk Streamer has a detailed tooltip (hover over setting label to see), however if you would like to view even more detailed information, you can take a look at the Prefab Streamer Section within the Chunk Streamers Chapter.