The Heat acquire Ja in a trade. In exchange, they send Mitchell, Jakučionis, Rozier, the 2028 first-round pick, and two second-round picks. Even if his value has declined, acquiring Ja and trading Loggia is a reasonable price to pay. (In fact, you could say the Heat made a favorable trade.)
Memphis loses Ja and gains Monk, Mitchell, Hield, two first-round picks, and one second-round pick. Considering his poor performance and conduct this season, he will be closely scrutinized. Still, getting two first-round picks is a good deal (especially considering Young had no draft rights).
For the Warriors to acquire MPJ, they must give up two first-round picks. If they're going all in on Curry, they should do it. (It doesn't necessarily have to include pick protection.)
It's doubtful the Nets will be satisfied with this. Adding a draft pick or swapping Memphis' first-round pick for the Nets' second-round pick would be a viable option.
Are the Kings happy that they got Kuminga?