Outdated chests' loot tables get deleted when updating to 1.18.1

The bug

When updating an old world from for example 1.12.2 to 1.18.1, any yet un-opened blacksmith chests in villages get their contents deleted.

Expected behavior

I expected the village chests' loot tables to be instead turned into minecraft:chests/village/village_weaponsmith instead of being deleted.

How to reproduce

1. Create a world in 1.12.2

2. Find a village with a blacksmith
3. Update the world into 1.18.1
4. Open the chest
->❌ The chest is empty due to the loot table it contains no longer existing