I found an overhead shot on my phone of the area Manta sits on before Manta, but also you can see some of the track pieces laying on site waiting to be built:
Apparently SeaWorld told the media prior to park opening that Manta would be loading every row. However they indeed are loading every other row like the other coasters.
Can I just note how much I love Manta? Inject that lift hill music followed by an insane pretzel loop, and swooping around water, rockwork, trees, and bushes low to the ground directly into my blood.