If you want to ensure the exclusion is updated before the audience query runs, you should place the audience SQL Query Activity in a step after the exclusion SQL Query Activity. This way, the exclusion query will run first and update the data extension with the subscribers who should be excluded from the send. Then, the audience query will run and pull the subscribers who meet the criteria for the send, excluding those who were filtered out by the previous query. Placing a wait step between them or placing them in the same step will not guarantee that they will run in the correct order. You can learn more about this in the [Automation Studio Basics] module on Trailhead.