When curing a villager of the zombie affliction, I noticed only those who already had professions when becoming zombies will offer discounts when cured. No difference whether the trade was locked (already traded with) or not, but no unemployed villagers offerred discounts when taking up a trade after being cured.

To reproduce:

Set difficulty to hard.

Create a small village of 2 beds, spawn in two villagers (preferably in separate rooms for convenience). Restrict work access to only 1 workstation, so only 1 villager has profession. Make sure both are capable of taking up trades (no nitwits or baby villagers).

Spawn 1 or 2 zombies in order to let the villagers be attacked and turned into zombies. Dispatch of the spawned zombies for convenience.

Use weakness potion and golden apple on both villagers to cure them. Observe how 1 of them takes up a profession again (due to the single workstation placed earlier).

Place 1 more workstation so the other villager can connect and both now have trades.

Expected result: 

Both villagers offer their wares at reduced prices (owing to being cured).

Observed result:

Only the villager who already had a trade (not necessarily a locked trade) will offer a discount after being cured. the villager who was unemployed before changing offers no discount, even after being both cured and taking up a trade.