Bungie announced they would be delaying the download of additional files needed for Destiny 2: The Witch Queen due to unexpected problems.
Destiny 2 : The Witch Queen will require a chunky download for all platforms, on the account of being an expansion to an already chunky game. That said, PlayStation 4 users will need to download a lot more than the rest of the eligible platforms but the overall install size will be reduced. For a brief comparison, download size on PC was 21GB while PS4 players will need to download 72GB across all the required content.
It's not ideal but most fans hoped they would be able to finish the download before the expansion officially launches on February 22, 2022, at 9:00 AM PT / 5:00 PM UTC. That will not be the case as Bungie announced that due to an unforeseen issue, PS4 players still can't download the required content .
They will be able to start the download at 9:00 AM PT / 5:00 PM UTC, when update 188.8.131.52 is deployed. In other words, they will be able to start the download when the expansion launches.
This would normally be a bummer but keep in mind that the hype over the new expansion is almost certain to lead to long queues and chances are you will miss very little, if anything, during those first hours.
Just make sure you kick off your download as soon as possible.