The NFL can be a brutal work place. You are loved one second, and hated the next. Employed in one instance, and released the next day.
This is what happened with Pittsburgh Steelers ILB Jon Bostic. After the Steelers traded up 10 spots in the 2019 NFL Draf to select ILB Devin Bush, and after signing ILB Mark Barron in free agency, the team decided to cut ties with Bostic.
The writing was on the wall for Bostic after those aforementioned moves. There just aren’t enough roster spots for a player like Bostic, who doesn’t play special teams.