I have seen some new body panels be delivered with quite a few areas where the primer is thin or missing. So, there is a chance for some slight oxidation on the hood, especially in areas that may not be covered completely by the current primer.
Remember however, your painter should be doing a complete surface prep before painting your new hood, including a good primer coverage. So, I wouldn't be too concerned for it to see a few weeks of exposure.
:cheers
DP