The issue:

The /summon command says it spawns an entity even when it cannot be spawned and returns positive feedback.

This could mess up a situation where such command is used: /execute store success score <...> <...> run summon armor_stand 0 69 420420, for instance.

How to reproduce:

1) Create a world with cheats and no datapacks

2) Attempt to summon an entity, far away from your coordinates: /summon armor_stand 5 63 45555

3) Take notice as the chat says "Summoned Armor Stand" even though the entity was not created, as you can find by running /say @e[type=armor_stand] - obviously because the chunk is too far away and is not loaded

What is happening:

The command returns positive feedback despite chunks being unloaded

What should be happening:

The command would return negative feedback as the entity could not be summoned due to the chunks being unloaded