But all will likely bounce back with new additions.
From SB nation:
Here are the squads that will be looking to replace the most professional talent in 2017-18.

North Carolina Tar Heels
Players Drafted: Justin Jackson (15), Tony Bradley (28)
Few teams were hit harder by early declarations than the reigning national champions. ACC Player of the Year Justin Jackson was not a surprise, but freshman big man Tony Bradley was. His departure made the Tar Heels just the third team in the one-and-done era to win a national title with a one-and-done player.

Kentucky Wildcats
Players Drafted: De’Aaron Fox (5), Malik Monk (11), Bam Adebayo (14)
As has been the case more times than not since John Calipari arrived in Lexington, the first round of the NBA draft wasn’t even halfway finished before three Kentucky players had heard their names called. What makes this year different is that the Wildcats also lost a pair of early entrees in Isaiah Briscoe and Isaac Humphries, who went undrafted. The good news for Wildcat fans is that athletic freak Hamidou Diallo opted against becoming the program’s first “none-and-done” player, and will play as a freshman for UK in 2017-18.

Oregon Ducks
Players Drafted: Jordan Bell (38), Tyler Dorsey (41), Dillon Brooks (45)
Oregon’s run to the 2017 Final Four came at a price. Brooks, Bell, and Dorsey all declared early and wound up being second-round picks. The Ducks also lost Chris Boucher and Dylan Ennis to graduation, leaving little for Dana Altman to work with in 2017-18.

Gonzaga Bulldogs
Players Drafted: Zach Collins (10), Nigel Williams-Goss (55)
Zach Collins becoming the first one-and-done in Gonzaga history wound up being the right decision, as the versatile big man went 10th overall in the draft to the Portland Trailblazers. Star guard Nigel Williams-Goss passed on the opportunity to be college basketball’s likely preseason national Player of the Year in 2017-18 in favor of getting his professional career going. Even if Williams-Goss doesn’t wind up making the Jazz’s roster, it’s hard to fault the decision of a 23-year-old whose stock will likely never be higher than it was coming off his All-American season of 2016-17.

UCLA Bruins
Players Drafted: Lonzo Ball (2), T.J. Leaf (18), Ike Anigbogu (47)
Spearheaded by Ball, UCLA’s talented freshman class helped take a team with a losing record and turn it into a squad that won 31 games and advanced to the Sweet 16 in 2017. Ball and Leaf seemed like one-and-done players from the moment they stepped on campus, but the departure of Anigbogu, who played sparingly in 2016-17, came as something of a surprise. Double-figure scorers Bryce Alford and Isaac Hamilton are also gone from the Bruin program because of graduation, but head coach Steve Alford did receive good news when both Thomas Welsh and Aaron Holiday put their professional careers on hold.

Duke Blue Devils
Players Drafted: Jayson Tatum (3), Luke Kennard (12), Harry Giles (20), Frank Jackson (31)
No program had more players selected in this year’s draft than Duke, which shouldn’t come as much of a surprise considering the amount of hype surrounding the 2016-17 Blue Devils. While that hype ultimately went unfulfilled, it didn’t keep three Dukies from going in the top 20 of the draft, and another from being the first pick of the second round. Of all the players with a decision to make, only junior Grayson Allen opted to return to Durham for one more season.

SMU Mustangs
Players Drafted: Semi Ojeleye (37), Sterling Brown (46)
Three of SMU’s top four scorers are gone from a team that won 30 games and both the AAC’s regular season and tournament titles in 2016-17. In addition to Ojeleye and Brown, versatile forward Ben Moore — who has signed a free agent deal with the Pacers — is also gone. The only double-figure scorer returning to Dallas next season is junior guard Shake Milton, who averaged 13.0 points and 4.5 assists per game in 2016-17.