The bug

Containers that have a loot table applied to it will drop its contents when removed with commands. This is undesirable because the items will always need cleaned up afterward. It's worth noting that containers with items placed inside do not drop their items when replaced in the same manner.

Steps to reproduce:

• Install the attached world file. Inside is a chest with some dungeon loot, and a structure to place one down more conveniently (name is mystructure:dungeon_chest). Take care not to open the chest to generate the loot, the chest must be untouched.
• Remove the chest block with commands. For example: /setblock 0 -60 3 air

→ The chest drops a loot table, making a mess everywhere.