Title says it. After the Ja trade, they need to dump a guard. Jrue would certainly elevate the team's success, but I don't think they make it out of the second round (I don't think they make it out of the first round, but I'll be nice) with or without him.
This gives the Blazers more positional flexibility with Derozan, and some good bench scoring with Monk.
Kings get an adult in the room to mentor Acuff and teach him some defense... maybe.
Frankly this (maybe) raises the ceiling of Blazers by a few games and helps gives depth in case of injury. Kings suck and will continue to suck; however, you have Jrue in the building for a year to help teach good habits and then you can do buy him out if you want.