The point of Midway was to force FDR to sue for peace.
The Japs had no intention of invading and holding the Hawaiian Islands.
I thought the point of Midway was to push the USN further east to prevent another Doolittle raid which was a major embarrassment for the IJN. There was a simultaneous invasion of the Aleutians, which was meant to lure the USN north, but thanks to code breakers, the US did not bite. Establishing airbases in the Aleutians was intended to protect the home islands.