Villager was likely chosen before New Leaf even released... City Folk was no more successful than the previous games. Actually it was much less successful than Wild World.He once said animal crossing and things that were peaceful weren't "fit" for smash but over the years it made a boatload of money and he magically found a way to put villager on the roster.
And demand for Villager had pretty much all but vanished due to Sakurai's comments.
Sakurai changing his mind isn't inherently due to business reasons. Especially since AC got less successful between Brawl and 4's initial roster selection...
Also,
There's a huge difference between a few years and a few months.
And Sakurai still hasn't really changed his stance on Ridley since Brawl.