Add note

docs/content/concepts/partitions-schedules-sensors/backfills.mdx

@@ -149,6 +149,8 @@ To launch and monitor backfills for a job, use the [**Partitions** tab](/concept
    - **For the default run coordinator**, the modal will exit after all runs have been launched
    - **For the queued run coordinator**, the modal will exit after all runs have been queued
 
+**Note**: If the job targets assets that have backfill policies, the assets' backfill policies will control which runs are launched.
+
 After all the runs have been submitted, you'll be returned to the **Partitions** page, with a filter for runs inside the backfill. This page refreshes periodically and allows you to see how the backfill is progressing. Boxes will become green or red as steps in the backfill runs succeed or fail:
 
 <Image