KP has been a mess all year and he threw shade at Luka earlier in the year. They quietly (or not so quietly) were looking to ship him before the deadline this year.
He doesn't rebound, he can't protect the rim, he can't take anyone in the post and if he isn't hitting his jumper, he's just a malcontent that is hurting your team.
I think Kawhi is staying in LA and they would be much more likely to trade PG, but if Kawhi wants to be on a team where he doesn't have to bear as much of the load, he should go to Dallas.
Regardless, Dallas desperately needs a better #2 for Luka.