NFL teams start releasing players as soon as they start drafting new ones, pretty much. Perhaps a day or two later. Even the Pittsburgh Steelers announced three cuts on the final day of the draft after they signed three more college free agents than they could fit on the 90-man roster. But that’s not the only reason players get cut.
When you add depth to a position, especially when you do so with a premium draft pick, the players at the lower end of the depth chart instantly become less valuable, less likely to make an impact or to be on the team, and more likely to find himself looking for work in short order.