No, original means they are in their "original state"-all villagers, invited in via the campsite/moved in
come pre-packed with their own unique shirt and house. These are original villagers, however, if they change their furniture, clothes, or catchphrase, they are unoriginal.
Like for example,
original Julian has a twinkle tee, his catchphrase is "Glitter" and this room:
However, an example of an unoriginal Julian is mine: he still has a twinkle tee (but he can change it if you give him one/put up patterns in able sister's), his catch phrase is "Lil' ears" and he has replaced most of his furniture with the rococo series.
Hope that helps