I'm honestly very surprised Woolio was not brought back in the 2.0 update as a Smug villager. Would've felt like a slam dunk to me.
I imagine whenever AC6 comes out, they'll probably focus on bringing back more original villagers, perhaps with some personality adjustments to try and even out the number of villagers in each personality. I'd wager at some point the series that we'll have everyone back who's been cut from the series minus the promotional villagers, which I don't think will be coming back unless they do another Amiibo (or whatever the next thing is for the next console)-style promotion. (And also maybe no Champ).
I imagine whenever AC6 comes out, they'll probably focus on bringing back more original villagers, perhaps with some personality adjustments to try and even out the number of villagers in each personality. I'd wager at some point the series that we'll have everyone back who's been cut from the series minus the promotional villagers, which I don't think will be coming back unless they do another Amiibo (or whatever the next thing is for the next console)-style promotion. (And also maybe no Champ).