When an object changes zones, it becomes a new object with no memory of its prior existence (with a few exceptions that don't apply here). So, if you Cloudshift a blocker, even though the creature on the battlefield now may be the same physical card, the game sees it as a completely different object. The creature that blocked no longer exists.
Private Mod Note
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Rollback Post to RevisionRollBack
Level 2 Magic Judge
Cards do what they say they do. No more. No less.
If a creature leaves the battlefield, it is removed from combat. It will not deal nor receive combat damage.
When an object changes zones, it becomes a new object with no memory of its prior existence (with a few exceptions that don't apply here). So, if you Cloudshift a blocker, even though the creature on the battlefield now may be the same physical card, the game sees it as a completely different object. The creature that blocked no longer exists.
Cards do what they say they do. No more. No less.