Supposedly he was open to it but the team wasn't. They thought he'd disrupt the chemistry of a young team and they're right. Durant has some downsides at this point in his career but scoring isn't one of them.
As for Jalen Williams, that's a tough decision. He didn't have a good playoffs last year but that was his first one. This year has been a repeat. If it happens for a third time, then that's what you are and his trade value starts to take a hit. He's a legitimately good all around player. He can do everything on offense and might be one of the most versatile players in the league on defense. They can easily have that with him for another 10 years but will that get them a title? Working with a Durant swap, that's trading a decade of really good for one title.
I don't think they'd do it but I promise you that both teams would take the call. Phoenix gets a good pairing with Booker, Jalen likely gets more money there than he would with OKC, Phoenix gets some draft picks, and they just ride out the Beal contract. OKC gets Durant along with Chet and Shai.