If they didn't, yes. There is of course special redemption in God's plan for the people of Israel, but I've never seen anything in the Bible to indicate it extends beyond the grave.
MM
For one, many see Romans 10-11 as the two branches of the tree becoming one as in the Christian Church and the Jewish Faith being melded again together in the Hands of God. If so, then where is the first branch from, if there are no saved Jews, there would not be two branches.
For a second thought, Is a Mexican saved if they believe in the name of Yesus Christi? Is the name Jesus magic, or is it Faith that is seen by God as rightiousness and makes us sons of Abraham?
So what if they have faith in the Messiah, yet do not see who He is? There is a clear indication in the Bible that shows that might be enough, as Christ descended into the depths of Hades/Paradise to raise those who were in Paradise and set them free. Paradise is empty now, it is not refilling for a second resurection. The question then is, how if the Judgement Day has not happened did the souls get sorted?
Simple, those in Paradise believed in the Messiah, before he came, And before they knew his name.That leaves us on the thin ice that God changed the rules for salvation after Jesus, and makes God not the same today as He was yesterday. Hmmm...
Another part from the Bible that addresses this issue is when the sons of the Cohen used the name of Jesus to attempt to cast out the demon from the demoniac. They stated a command to the demon in the Name of Jesus that Paul preached. "And the evil spirit answered and said, "Jesus I know, and Paul I know; but who are you?" (acts 19:15) So it was not the name that had power but the faith in the Messiah, because they had faith in the Name or they would have not have used it, but faith in the Name is not enough, it is faith in the Messiah.
So, is it enough to believe that the Messiah will make a way, and believe in trust in that Messiah? Or must they also know His name because faith in the Messiah is not enough? That indeed is thin ice, and I will not going to go there.
I have faith in the Messiah. I suspect I know His name. In english it is Jesus. But to say that a man who has spent his life in faith in God and the Messiah is not saved? I suspect the Messiah might argue with that. My guess is that God will surprise us all with His Justice in the end.