rennsportCloseout is usually at end of day. Speaking purely in generalization, you get the notice because a label was generated. The end-of-day report goes from the warehouse to UPS for ingestion/processing, and some time during the night the outward-facing systems are allowed the information. Theoretically the warehouse folks could hit the closeout button after every package, but that's just irresponsible on their part.
c/n: this is normal. it's all good.