All agencies that have submission supported should get releases attached correctly.
Please note that releases are attached on the separate step (submission) and not right during the upload. The submission process happens either automatically (as soon as images appear in unfinished section of the agency and the program's timer or auto checking reaches zero) or manually (if you click "Submit now" button with agency checkbox checked).
Thus, there is a period of time when images don't have categories, releases or any other custom agency information filled and are not sent to the reviewers.
If there will be any errors during submission (the program will notify you about them) files won't get submitted and won't have this information.
If you don't have the program running or agency's submission checkbox checked when the files appear in unfinished section of the website, they won't get submitted either.