Not sure where the chucker label comes from, but he's 3rd in usage behind Sullinger and Green and ahead of Rondo and Bass. Pretty much where you'd expect him to be. He's an average offensive player based on points per possession with his strength being as a spot-up shooter where he is very good, as opposed to being an iso or PandR player where's he's not. His handle is below average and he has tunnel vision IMO as a distributor - the game doesn't slow down for him offensively.
Defensively, he is still a superior defender this year based on points per possession allowed after being elite in the past. Maybe it's a function of ankle injuries. Still an elite off-the ball defender, but has had issues in isolation this year.
Overall, it seems like a lot of people have soured on him here and I suspect it was because their expectations were unrealistically high when he was in his second season. Nonetheless, he is almost exactly what he was coming in according to Draft Express, except he's a better 3FG shooter now.
My problem with AB is that he's a SG who doesn't provide the offense you need from the position and he's paired with a pass-first PG in Rondo. He could be a good fit for a team looking for an elite backcourt defender to pair with a scoring PG. In the end, DA makes him a qualifying offer and the market decides his value. Given how conservative the market was at the trade deadline, his value may well be lower now than when earlier negotiations were occurring.