Do you believe in Universalism? By your words I think so.
In that context, reformed Christians believe that "all" refers to Jews and Gentiles. The whole context points to this direction...
The Gospel of John chapter 12 talks about the final events of Jesus' public ministry. The final words of the Lord for the people are stimulated by the arrival of the Greeks who were looking for Jesus (John 12:20-22). When the disciples spoke about it to Jesus, He said: "The hour is come, that the Son of man should be glorified." (John 12:23). So this is the context that leads us to Jesus' words in verse 32:
"Now is my soul troubled; and what shall I say? Father, save me from this hour: but for this cause came I unto this hour.
Father, glorify thy name. Then came there a voice from heaven, {saying}, I have both glorified {it}, and will glorify {it} again.
The people therefore, that stood by, and heard {it}, said that it thundered: others said, An angel spake to him.
Jesus answered and said, This voice came not because of me, but for your sakes.
Now is the judgment of this world: now shall the prince of this world be cast out.
And I, if I be lifted up from the earth, will draw all {men} unto me. " (John 12:27-32)
Does the cross draw all men unto Him? Is that what the Bible really teaches about the cross? Certainly not! The cross is foolishness to the Gentiles and a stumblingblock to the Jews, as Paul taught:
"For the Jews require a sign, and the Greeks seek after wisdom:
But we preach Christ crucified, unto the Jews a stumblingblock, and unto the Greeks foolishness;
But unto them which are called, both Jews and Greeks, Christ the power of God, and the wisdom of God. " (1 Corinthians 1:22-24)
Paul knew this truth in the same way as Jesus taught, "for those who are called, both Jews and Greeks ...". For whom is Christ the power and wisdom of God? For " those who are called." Is the salvation for all men? No, because the Gospel is foolishness to those who are not called.
These considerations, along with the immediate context of the Gentiles seeking Christ, make it clear that Jesus was saying that if He was raised in the crucifixion, He would bring all men, Jews and Gentiles, to himself. It is the same as saying that there were sheep which are not of this fold (John 10:16), ie, this is related to the Gentiles who have become one body in Christ (Ephesians 2:13-16).