As others have said, the new school must "absorb" that scholarship next year.
It's pretty darn late in the game to really make adjustments this season. Can you imagine if a Penn State DT came to Nebraska and Bo turned around and cut Steinkuhler or Rome? Total bush leag
The one year "freebie" protects the exiting players and gives them a full calendar year to test their mettle with another squad. I actually think it's perfect because it doesn't harm those players and hamstringing their chances with another team. Otherwise they'd all wind up playing for Temple or San Diego State.
One advantage to this is for seniors. Since they only have one season left, they get a free pass at any school. A guy like Silas Redd could transfer just about anywhere and make a splash without too much repercussion. Honestly, the Huskers should make a play for him, IMO. He's like a free one-year sniper. Just plug him in where needed and reap the benefits. No loss in scholarships and our HB stable is beefed up.
Plus, a guy like that could bring in a wealth of information to the other players and coaches. He's probably got a few "go-to" plays up his sleeve that a smart OC could meld into their attack.