Irving and Durant both are leaving the team surely as it seems. They have both wanted their trades as soon as possible. Actually Irving was closer to be traded but the team made a decision and decided to give priority to Durant's trade. I have heard that Miami Heat and Phoenix Suns are the teams Durant want to go now.
Durant going to the Heat would give the Heat a big boost even if they will trade Butler for him.
IMO, I believe that Durant is more clutch and more team player than Butler, so I'm okay with that trade if that will happen.
I don't think that's the right move. Butler created a brotherhood there and taking him out in exchange for Durant will most likely ruin that chemistry.
What I want for the Miami Heat to target is a point guard. Kyle Lowry seems to have lost his touch and is playing lesser minutes at 36 years old.
If they will focus their playmaking with Gabe Vincent and Tyler Herro then aim for a shooting guard. They didn't use Duncan Robinson last playoffs because of his lack of defensive skills.
A strong guard who is capable to do both will be their best choice.