Sorry, I should've elaborated. This is part of a TL I'm writing with a PoD in 1933. The short of it is that WWII is generally accelerated, and starts in March 1939 instead of September. There are several big differences. Most importantly to this discussion, Japan is already at war with the wallies, but doesn't really do much other than take the concessions and ports in China and fight a few inconclusive naval battles (the Japanese invasion of China is going worse than OTL, so they're distracted), and British-American relations have been badly damaged by a series of actions by the British (the British are much more aggressive in this TL, even preemptively intervening in Norway to stop the Germans from invading), the war generally follows history, but ahead by a few months. The embargo begins in January, and is even more harsh (because of the aforementioned significant differences), and the Japanese decide they can't wait for the Shokaku and Zuikaku, but still need to launch a crushing surprise attack on Pearl. At the expense of their other operations, the Japanese decide to launch the attack anyways with everything they can scrape together. Because of the limitations on their fleet, the Japanese don't attack the Philippines immediately.
Thanks for the info Calbear
(Probably should've put this stuff in the initial post, but oh well)