The Nittany Lions will open the season as a top 15 squad in the Coaches' Poll for the third consecutive year.
Thornton Jr., the fourth-best wide receiver in the next recruiting cycle, was the first player in the class of 2021 to pick Penn State.
Meiga, a wideout from Montreal, Canada, picked the Nittany Lions over Louisville, Cincinnati, and Buffalo, among others.
Elksnis picked the Nittany Lions over Ohio State, Florida, and Florida State, among others, and he joins Donte Thornton Jr. in Penn State's recruiting class of 2021.
Barkley made his debut on the annual rankings of the best players in the NFL at No. 16.
The former Nittany Lion inked a contract with the Bills, who are dealing with a bit of an injury crisis at tight end early in training camp.