User blog comment:LostInRiverview/The Sims Wiki News - 17th July 2014/@comment-1997588-20140717172759

The TS2:UC FAQ at SimsVIP says this:

Additionally, we don’t currently have plans to make the Ultimate Collection available for purchase, however we are still discussing options in regards to its availability.

It doesn't mean it won't be available for purchase, but there's a higher possibility it won't rather than it will...