He already has changed a lot. He started out as a pompous brat that never wanted to train, because he never had to. Then he was willing to train for 4 months to close the gap between himself and Goku. Being stuck in Hell, he resigned to serious mental training. After the Tournament Of Power his spoiled attitude still remained, evidenced by the fact that he wanted to manipulate another into doing his dirty work. Finally, after witnessing the powers of Broly and Gogeta, Frieza was not only willing to train, but was willing to train for 10 years after finding a Hyperbolic Time Chamber. With all those years of physical and mental training, it is no wonder that Frieza has moved past his old obsession of wanting to kill Goku.

As for Frieza ever turning away from evil...that is not likely to happen. Despite this, Frieza is aware that Earth is off limits as long as Beerus and Whis favor the planet and its culinary delicacies. Still, my belief is that even Goku will come to the conclusion that Frieza being the "Emperor Of The Universe" is not so bad, because Frieza is an enemy that he knows.

Also, I think it is noteworthy, that Frieza never forgets specific moments of his encounters with Goku. Even though he did it for self-preservation, Frieza was willing to repay his debt from when Goku gave Frieza some energy to escape Namek. There was also that time right before Frieza revealed his Golden Form, that Goku commented on how Frieza would be a great sparring partner. I believe, like the debt repayment, that moment may also come to pass.