"Up all Night" And "Life of The Party"

I would say that they will be avaible longer. It doesn't say they are preorder only. They are part of the Digital Deluxe and several DVD editions.

Also DVD editions are usually avaible a lot longer then just until launch so even if they do no longer sell those editions on Orgin, you should be able to find the DVD editions.

Here's more info on the editions: http://answers.ea.com/t5/The-Sims-4/INFORMATION-Which-editions-are-there-and-what-s-the-difference/td-p/2962306