Jesus denied life after death, too.
Haha. No, I am not attempting to come up with the latest version of "what Jesus really taught." Jesus does not deny the idea of the bodily resurrection; he clearly teaches it, and in the utter uniqueness of his person, practices what he preaches.
In the Western world we tend toward bare materialistic view of life and death which clash with the Scriptural version of those concepts. One result is serious misunderstandings of the veiled, more limited expressions of the doctrines of life and death in the Old Testament. So, before answering the question at hand directly, I must consider an essential background question—
Is Job's View of Death Incompatible with a Belief in the Resurrection?
Many Christians understand Job (and the Psalms) to speak of death in a much different way than Jesus did. Big if that is true, what did Jesus mean when he said, "He who believes in me will never die"?
It's one of those verses that is often quoted, best less often grappled with. Either we must be willing to admit a different sense of death hear than the one we commonly use, or we must admit that Jesus lied.
So when I say, "Jesus denied life after death," it's not that he denied the life, but that he denied the death. That's what eternal life is about in his teaching as well. Eternal life is not something that begins in the future, but now.
But if Jesus uses this sense of death, why must we insist that the Old Testament writers used a more materialistic sense of death? If this were merely in Job, it would not be a problem, because we can disagree with Job without denying inspiration. But the Psalms speak of death in much the same way. "How can I praise you from the grave?" etc. The answer is, you can't—but that is because death is defined as separation from God. To know God is to live. That isn't fancy words and ancient ideas and poetry. That's reality.
How clearly did the psalmist himself perceive that? I do not know. The degree to which the Old Testament prophets understood what they said is somewhat mysterious. But one thing I can say for sure: before we start to deprecate the way that the Psalmist or Job speaks of death, remember that Christ spoke of life in a way that coalesced with that the way they spoke of death.
So is Job's view of death incompatible with a resurrection? Absolutely not. The dark expressions about death in Job and in the Psalms are a call for and perfectly illustrate the need for resurrection, but do not contradict it. Whether they include is less certain; they certainly do not preclude it.
Interpreting Jesus through our own cultural lens, we often have a rather dull view of eternal life as life that simply does not end. In the context of such dour statements about Sheol, eternal life means a lot more. It means not only perpetual existence, but residence in the sanctuary.
I started by saying Jesus denied life after death, too. Now, having explained myself, I'd like to reverse the terminology, and say that neither Christ nor Job denies an afterlife!
But is Job 19:23-27 an Early Statement of Belief in the Resurrection?
Quite honestly (this is an abrupt ending, but) I do not know. I hope to do more research and work on this answer further (it needs specific references to verse numbers, etc., but I need to not stay up any later tonight). I would like to look into the issue more closely.
But the conclusion of the previous section is very important in forming an opinion on this. Essentially, at this point the translation issue it not whether Job contradicted himself; that is taken out of the equation. It is possible that there is a tension of mood.
Until further notice, then, my thesis is: It is conceivable that this is a statement of faith standing out amid his grimmer speeches. Forgive the half-baked answer; I see even the possibility as being significant enough to be worth arguing for.