If you upload your release before the indicated release date it will be available as pre-order on Amazon, iTunes and Juno.
This means: Your release can be pre-ordered, but will not be available until the release date you indicated during the upload.
During the pre-order period, the album can only be pre-ordered completely. Individual tracks can be acquired after the official release. Audio snippets are not available during the pre-order period.
As of right now, the pre-order period cannot be documented in the trends due to technical circumstances. The sales which occured in the pre-order period will be listed after the official release.
Important: Unfortunately Amazon does not always take your pre-order date into consideration. Ergo, in some cases your release will be available on Amazon for pre-order right after delivery.