Allen spent the entirety of the season on Pittsburgh's practice squad and played in two games in 2018.
Gray led efforts to launch LionPATH and oversaw the university's financial performance.
Bowen will call Penn State's plays in the Cotton Bowl while retaining his position as tight ends coach.
Clifford missed Penn State's regular season finale due to an injury, but he'll be back at the helm of the Nittany Lions' offense for this year's Cotton Bowl Classic.
The Nittany Lions have no shortage of talented pass-catchers in their 2020 recruiting class.
"Canada is starting to turn into the northern tip of Pennsylvania from a recruiting perspective."