All the "friends" of Job spoke wrongly about Job and about God, and God rebuked them.... but the last speaker, who was simply a young passerby, spoke rightly of God, and judged Job rightly, and was not rebuked by God.
Exactly.
Job had lamented that there was no "daysman" or "umpire" or "mediator" between him and God who could lay his hand upon both of them or mediate between the two...
Job chapter 9
[32] For he is not a man, as I am, that I should answer him, and we should come together in judgment.
[33] Neither is there any daysman betwixt us, that might lay his hand upon us both.
...and Elihu told Job that he was there according to Job's wish or that he was going to mediate between God and Job in God's stead:
"Behold, I am according to thy wish in God's stead: I also am formed out of the clay." (Job 33:6)
IOW, Elihu is a type of Christ in this account in that he is a mediator between God and man and, as you rightly noted, God rebuked Job's three friends, but he never rebuked Elihu because Elihu's testimony was spot on. What then did Elihu repeatedly address with Job? Well, he repeatedly addressed PRIDE with Job as the same was Job's problem and the same is what Job ultimately repented of. Elihu tore Job's "legal case" against God to pieces...and rightly so. I'll be happy to point out the same in scripture if need be.
