What everyone else said, plus IMO their team is already so loaded so there’s no pressure to bring along the new guy quickly when that would just raise his market value at a time when you’ve already got too many star players to carry on one roster.
With high production per minute played, I suspect the Grizz want to first lock up some of their other players but must be counting on Edey being a big part of their longer-term plan too.
The other thing is he’s been picked on a lot. Not just with Draymond Green, who tried to twist his ankle on the ground and antagonize him in multiple games after that, but similar things have been happening all season when he’s been in the game. If you didn’t see Drew Eubanks’ running hockey check into his shoulder about a week ago, it’s worth looking up. Nobody is worried about Zack Edey losing a fair fight, and I don’t think he has a reputation of being the aggressor in any of these situations, but people are messing with him (IMHO) out of fear that he could end up creating a movement of talented, big men that change the league. If you’re a 6’ 8-10” NBA player who plays Center or PF, you don’t wanna see basketball taken back to the era of dominant bigs.