The long controversial blackout rule has been rescinded according to multiple reports from the league owners meetings. It isn't permanent at this time, it is just for the 2015 season. Call it a trial period which would suggest that if the league can revisit the rule at next year's owners meetings and decide whether they want to bring it back or make it permanent.
Over the past few years, the blackout rule has not required a sellout to be avoided being implemented. A team could avoid a local blackout by selling 85% of tickets by the Friday cutoff time.
Thanks in part to the 85% rule as well as the tarps placed on Mt Davis, the Raiders haven't been blacked out in the Bay Area market since December of 2012 -- a streak of 16-straight games in Oakland locally televised. The only time it has ever come into question has been for an out of division game against a lackluster opponent. That game in 2012 was against the Browns.
With the blackout rule no longer an issue, there is little reason for the Raiders to continue placing the tarps on Mt Davis during games. They can open those seats to ticket buyers for those games.
The decision had to be made prior to the season as to whether to use them, regardless of whether it was a better selling game or not.. And many times over the past two plus season, the team has sold out their games and could potentially have sold a good deal more tickets had the tarps not been in place.