If Japanese land-based aircraft had ambushed the American planes and struck the carriers effectively, could they have turned the air war around?
Short answerThey might have changed this battle by disabling American carriers, but they would not have changed the overall course of the war.
NotesEffective land-based strikes against American carriers could have changed the Battle of the Philippine Sea by removing decks and aircraft from the immediate fight. Even a local Japanese success would not have reversed the wider war. The distinction separates a plausible operational counterfactual from an implausible industrial and strategic reversal.