So I recently updated to 1.14, and returned to one of the villages that I had previously visited. For the most part, all the villagers did not have any professions (when I clicked on them they simply waggled their heads at me). However, there were two Librarians in the village.
These were the only two Villagers I had traded with, pre-1.14. They had their pre-existing trades, though obviously in the new format.
Is this the case for this situation? Or is it just my luck?