The Arlington product is the No. 19 ranked point guard in his class.
Maryland's 2021 recruiting class rises to No. 8 in the nation with Graham's commitment.
Cornish is the No. 77 prospect in the nation per 247Sports.
Smith averaged 1.5 points in 7.6 minutes last season.
Smith averaged 3.1 points and 2.5 rebounds in 31 games last season.
Reese is the brother of incoming women's basketball guard Angel Reese.
Chol Marial and Donta Scott are the Terps' only frontcourt options for next season.
In a statement, Tomaic said he was open to returning to the Terps.
Watson averaged 36 minutes per game last season, posting 13.0 points, 3.6 rebounds and 3.4 assists.
Chol Marial, Donta Scott and Joshua Tomaic remain the Terps' only frontcourt options for next season.