I am not sure, but I think it’s possible that you are misunderstanding the Gemara.
And when Jews are killed by goyim, we are sad. We don’t rejoice the way the Arabs do. And we try to do all we can to prevent it. During the holocaust, the Gedolim tried to save as many Jews as they could – they didn’t say, “Great, they get to die al kiddush Hashem. Better they should die al kiddush Hashem now than die later not al kiddush Hashem.”
Also, we daven every day that the day will come when all the goyim recognize Hashem. We are hoping that Mashiach will come today and that no Jews will ever again need to die al Kiddush Hashem.
I realize that your answer to all this could be that one should daven that if he has to die anyhow (if l”a Moshiach comes after he reaches 120), he should daven to die al kiddush Hashem.
I have two responses to that:
1. You should just be davening that Moshiach will come before 120, and that the whole world will do teshuva and no one will murder anyone anymore (like RY basically said).
2. Even if there is such a concept (which I doubt), it only applies to people on that level. For most of us, we should just be davening to be on the level that we want to die al kiddush Hashem.