If Germany gets it (colony or protectorate), Japan will probably snap them up in *WWI. This might make them feel less cheated out of Their Share of the Loot, which might in turn affect Japan's political history or even their actions in China. Never mind all the arguments about Pearl Harbor and the Southern Strategy.![]()
If Spain keeps it, or France or the Netherlands get it, Japan could very well get an opportunity to grab it.
An OTL WWI except with the Germans in the Phillippines is very interesting. I think it goes the way you say, with Japan taking over.
The US won't like this, but if Japan's meddling in China decreases as a result, the practical result is probably much less tension between the powers.
You might even get some kind of earlier US commitment to China, since in TTL the US will have its imperial ambitions frustrated and won't have had the eye-opening experience of the Filipino Insurrection. You may also have a greater US presence in Central America for the same reasons.