I did reset so many times... and I never got a smug or uchi starter. So yes, I guess these personality types are the ones that move in later on.
I also noticed... if you get for example peppy, jock, lazy, normal and cranky as starters... the next three villagers moving in will be the missing personality types -> snooty, smug and uchi in no particular order. The 9th personality will be random and the 10th is a camper, so that one's random aswell.
In past games though, when one of the villagers moved out leaving your town lacking of one personality, the new villager would always be of the same personality type. (if you didn't play online with someone else) If your only peppy villager moves out, the new villager will be a peppy one to keep the balance.
I think that's different in NL. Nibbles, my only peppy villager, moved out (I had 9 villagers at that time, I didn't have the campsite), but the new one replacing her was Vesta, a normal villager, although I never visited someone else or had any visitors! I already had a normal one at that time, too, Ava!
So... I think it's pretty random once you got to experience all the personality types?