Kaiir Elam
While the first four players listed would be released if the Bills don't have a roster spot, Kaiir Elam is in a different situation as it would be highly unlikely for the team to just release the former first-round pick outright. Instead, it would be a case of the Bills looking to trade Elam closer to the season as they have to cut down their roster.
The reason is that right now the starters at cornerback are Christian Benford and Rasul Douglas so Elam is likely heading for a backup role. If the Bills keep Elam in that role for another season, his trade value is only going to go down. They then have a big decision next offseason of whether or not to pick up the fifth-year option, which they wouldn't do based on the body of work to this point.
It would make sense for the coaching staff to give Elam a chance to prove he can be a starter, and potentially surpass either Benford or Douglas. However, it never felt like he was a good fit for this defense, and being only 23 years old with two years left on his rookie contract, the return might be the best it will be if he is not playing.
This seems like a wait-and-see approach and the Buffalo Bills can hope that Elam moves up the depth chart or plays well enough during the preseason that some team needing help at cornerback would be willing to make a trade.