I don't know about that. MacArthur did manage to convince Congress to try to build up the islands to a defensible level (which he thought could be reached by spring '42). If that process had started 6 months earlier, he should have been able to get up to that level by 7 Dec '41. (Of course, if he had, would the Japanese have attacked earlier?)I have to agree with the viewpoints stated here by CalBear and Oldbill. Logistically there is no way for the US to maintain a fighting force in the Philippines after Pearl Harbor. Given the state of training, level of equipment and the outdated strategic viewpoints of the US military in 1941 the Philippines were doomed from the start. It would have to be a very large POD (1939) to start to organize, arm and structure the force in the Philippines to have any different effect than what did happen to them. It was sadly a case of too little, too late for the Philippines.
I'm sure that MacArthur massively underestimated the Japanese, and probably overestimated his Philippinos, but I could see (with a build up starting 4 months earlier, say), that they could hold out (at least in the mountains) until some time in '43, and with the Japanese bogged down in the Philippines, they don't have the resources for New Guinea or Guadacanal, probably. Moreover, with MacArthur still holding out in the hills, he'd support the Central Pacific offensive by the Navy for his relief, rather than frittering away resources in the SouthWest Pacific.
So, once the Essexes start rolling off the ways, the US heads straight across the Pacific, and saves the Philippine holdouts (OK, both surviving soldiers, perhaps, but still).
Ya. Improbable. And Probably 'some holdout areas' rather than 'The Philippines are held', but still.