Compensatory picks are awarded to teams for losing unrestricted free agents. The level round of selection depends on the level of free agent that was lost. Considering the Raiders haven’t lost any high level free agents in a couple of years, it stands to reason that they only got a late round pick. They lost Chris Clemmons after the 2008 seasons, and he did not receive a high contract from the Eagles.
The free agents that are calculated based on players lost whose contracts have expired, not players who have been released.