Jackson is one of four starters from last year's team to opt out.
The group seeks to diversify the collegiate and professional coaching ranks.
Venerable is a three-star defensive back from Maryland.
Bam's older brother, Anthony, is a redshirt freshman defensive lineman for the Terps.
He previously committed to LSU in December.
Penn announced he would play at LSU.
Williams is the top-rated quarterback in the class of 2021.
Other universities have announced testing results, including Clemson, LSU and Kansas State.