Penn announced he would play at LSU.
Voluntary football workouts have been suspended.
The season is still due to start in early September despite the schedule change.
Williams is the top-rated quarterback in the class of 2021.
Maryland tested 105 student-athletes in its original screening.
Other universities have announced testing results, including Clemson, LSU and Kansas State.
Baker replaces Cory Robinson, who left the program in March.
“We remain optimistic about the return of fall sports," athletic director Damon Evans said.
Akingbesote is the fourth four-star recruit to commit to the Terps' 2021 class.