I think that when EA/Maxis started the game they meant surrounding areas of neighbourhoods to be used for such things that came later, like skating rinks, ice rinks and other additions that could turn up on unused territory with new packs. The skating rinks for instance, appear somewhere in all the worlds, even Newcrest.
I'd like to bet they were so surprised that they sold so many Sims 4 packs that they were forced to go 64bit due to the pressure put on them by Simmers and the new 64bit ranges of computers.
