Maybe God can keep the good that has happened while removing the bad. Is that possible? I don't know. If God is God, why not?
More than offering any particular solution, I am suggesting that, if God exists, then there could well be solutions to the problem of evil that we can't even imagine or begin to describe.
If you ask me to describe the mechanics of airplane flight for example, I wouldn't know where to begin. Not just the details, but I don't even know the language or symbols involved or what counts as an explanation in this context.
So what makes us think we are up to the challenge of accurately perceiving, describing, and concluding there is no solution to the problem of evil. If God exists it seems reasonable to suppose he knows more about it than we do, or can do.
Plus what if God simply eliminates suffering in the future. Atheists may say that's not good enough, but many believers may think that does preserve God's goodness. It's a genuine difference in moral judgement. Atheists may be convinced they are right, but if God and believers feel otherwise, how do you judge between the different perspectives. In the end you just get atheists shouting "I am right and you are stupid and callous if you don't agree with me". Is that really any way to settle the issue?