MacArthur might still repeat his historical inaction

How would MacArthur react to advance warning that a Japanese carrier force was moving east?

He might alert the Philippines or act aggressively, but he would probably repeat his historical inaction.

An explicit warning might put Douglas MacArthur's Philippine command on alert and could even provoke an aggressive attempt to bomb reachable Japanese targets. His historical failure to act decisively after Pearl Harbor weighs against that optimistic outcome. Better information does not automatically produce better readiness. The likelier result in this interpretation is another ostrich response.