If I cure a villager that was recently turned into a zombie, it chooses a different job site while keeping its profession. I had a butcher that worked on a lectern, and a fletcher that works on a barrel.
I broke the lectern, and the butcher chose a stonecutter as a job site. Then I broke that and the villager chose a couldron. I broke that too, and it returned to its original job site.
The behaviour of the other villager was similar.