Boone announced Thursday on Twitter that he would be leaving the program.
Ellis is the third player to transfer from Virginia Tech to the Terps in 2019.
Former Terps running back and wideout Tehuti Miles was signed Wednesday.
McDougle's commitment gives the Terps the No. 38 recruiting class in the country.
Locksley discussed his own past, his current team and his direction for the program.
DeGennaro is the Terps' second wideout in their 2020 class so far.
Boone is the Terps' first four-star recruit in their 2020 class.
Jackson is the Terps' 10th commitment for their 2020 recruiting class.
Thursday was the one-year anniversary of Jordan McNair's death.
Smith will join as a redshirt junior with two years of eligibility remaining.