The question is how Japan responds to this development.
A second wave concentrating on the more formidable US bases or ignore the Dutch East Indies to take out the US bases as soon as possible? Air power comparable to a medium carrier, a reinforced battalion and much more artillery is going to be noticed and Japan won't have any choice but to plan a response.
Again, that is the big difference in the early war years.
If the Japanese screw around in the central Pacific, they won't be able to grab the DEI effectively unopposed. The DEI was the entire point of the whole Pacific lunge. Even if the Dutch only have enough time to really wreck the oil fields and fuel storage facilities, the Japanese are toast.
Guam is not a good spot to invade, unlike many of the other Pacific sandspits both Guam and Saipan have actual terrain that can be used for defense, if not in depth, at least back from the water's edge. A Marine Defense Battalion and maybe a regiment (ideally a RCT) of army troops, along with say a squadron of Wildcats could be a REAL bitch for the Japanese to deal with considering the Japanese's serious issues with amphibious operations and the shoestring the entire Southern Strategy had to run on. Taking Guam with the propoaed defenses would be a divisional, maybe even multi-division action. The Japanese would have been hard pressed to find even an extra brigade, much less a division to conduct the assault.