From the Bloomberg article I read on this, 1 million barrels is a blip and won't meaningfully impact prices. The east coast consumes 3 million barrels PER DAY in the month of June.
Also, this action was mandated to happen by congress in a funding bill from March, mostly because the cost of maintaining gasoline reserves is much higher ($13/barrel/yr) than maintaining crude oil reserves ($0.30/barrel/yr).