How would Alaska-class ships have been used if available at Pearl Harbor?
Short answerThey would accompany fast carrier raids as surface cover able to delay a Kongo-class interception.
NotesAn Alaska-class ship would likely accompany each of the fast carrier raids conducted in 1942. It would probably lose a clean capital-ship duel with a Kongo. Its value is to hold or deter the enemy long enough for the carriers to escape or launch a decisive strike. That surface insurance would make American commanders less anxious about encountering Japanese heavy units during the raid. A large cruiser can be useful even when it cannot win the most dangerous fight by itself.