An essential aspect of a deal is when the music may be made available to consumers as well as when the music may be shown to consumers (see https://kb.ddex.net/display/HBK/Availability+and+Visibility for more details on how this is handled in ERN-3 and ERN-4).
When the visibility tags for a deal allow the DSP to show a Release to a consumer, the consumer will not only be able to see the Release but also add the Release to a playlist – even if the Release is not yet available.
The same applies to a track: When the track visibility tag for a deal allows the DSP to show a Release’s track listing to a consumer, the consumer will be able to add the tracks to a playlist – even if the Release (and thus the recordings) is not yet available.
This concept is also known as “Pre-Saves” or “Pre-Adds”.
The consumer will only be able to enjoy his or her playlist on street date, of course.