Hi Purplelipstick,
Are you talking about the loading screens when you open the game? It plays the Maxis logo, the EA logo, The Sims 3 logo, opening movie, then the loading screen. It always plays the newest EP/SP loading screen.
It sounds like for you that means the loading screen is Late Night (released after World Adventures).
All Sims 3 content is still there. You can confirm that by going into Edit Town and the three vacation towns should show as white boxes in the upper left corner of the current neighborhood.
You don't need to need to open the game from a different expansion or stuff pack. As it should all be there when you click the Sims 3 game in Origin.
MrsFlynn