Thanks for your answer!
It does make some sense what you say because I actually lost my save file this afternoon and saw already that it happened to other people, I guess it has something to do with that. It's no big deal to me but I guess it's something they need to focus on rn. Anyway if they actually postponed the launch on PS4 there should be some notification to it and I found no info at all.
Just to provide some more information: There actually was an "option" to pre-book the dlc in-game, slash option slash because it didn't work. The Ps Store opened @ "my Sims 4 downloads" and showed me my previous purchases. That option disappeared now, or at least I can't see it on the launch menu anymore. It was the only hint on my PS4 that there was a new dlc about to come, and now there is literally nothing.
My Ps Store is in Spanish so I thought it would be a bit pointless to post some screenshots.