I cannot even answer if evil is eliminated will there be free will in Heaven? I know we won't want to leave and/or be tempted to leave.We can appreciate God's goodness in the presence of evil. Unlike Adam who didn't know evil, Satan who didn't know evil, until they fell. We do! Because of it, we so appreciate his goodness and no matter what temptation that will come our way in heaven, if that could even happen, there would be no way, why? Because we knew how horrible evil was and now we can fully appreciate his goodness.
The presence of sin allows God to demonstrate his righteousness, the presence of sin allows God to demonstrate His love, and how else could He show the character of love that loves enemies and sinners if there were none? God endures this horrible assault on His everlasting holiness; He endures the horrifying blaspheming, history of fallen beings, He suffers it, the imposition it is on His purity to display His wrath to the fullest extent, to put Himself on everlasting display.
Why are we here? What is the theological answer? To glorify God and enjoy Him ever more. How do you glorify God? Here is how, you sinner, go get saved. Get saved so God can be glorified, that's it; this is the purpose of this entire universe.God knew we would sin, He knew we would rebel, He knew we would introduce evil, He knew it. So that he can send forth a savior born of a virgin, to live under the law to save us under the curse of the law so that, we can be a little trophy of his grace, he can always point to us as a testimony to his goodness. Ephesians 2:7
We wouldn't know how God is righteous as He is, everlastingly, and give him glory for it. If it hadn't of been for unrighteousness, we wouldn't know He's loving, as He is, if it hadn't been for sin, we wouldn't know He's holy, if it weren't for judgment.
How holy is God? So holy that He must send out of His presence, everlastingly, anyone who is not fit. Why of all this? That he might make known the riches of his glory, that is, He did all of this in order that He might gather into heaven a redeemed humanity who would forever glorify Him for all that He is. (paraphrased from Todd Friel)
bit.ly/whyevil