The Customs broker may file the Customs release request using the eHBL 8000 CCN in advance of Arrived, depending on the type of entry. For example, the Integrated Import Declaration (IID) can be submitted as much as 90 days prior to Arrival, and a PARS entry up to 30 days prior to arrival. The Customs status of the release request (i.e.: released) will only be visible after the 8000 CCN has been WACM / Arrived.
As per CBSA, RMD entries may be problematic if submitted prior to cargo arrival, as CBSA officers may either reject them if cargo not Arrived (possibly issuing an AMPS penalty), or just release them only upon arrival. Also, there are no status updates on RMD entries once submitted until they have been Arrived.