That is not what is considered Unibody cracking. That is an area where separate smaller panels were combined to build the Unibody. The seam should be tighter, but that may be how it left the factory.
Are there any signs of stress or separation at the spot welds ? Are there any signs of previously repaired accident damage ?
As long as the bump stop/coil spring mount and the frame rail show no signs of damage that area is simply used for attaching under hood components and locating the fender. It is not a major structural piece of the Unibody.
Here is a wreck I fixed, I had to remove and replace that panel.
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