I think for Britain especially, a lot of the reason for the embargo was simply to please the US, in the hopes that the US would soon join the war in Europe. Britain did not want to anger Japan, if possible, due to the tenuous state of Hong Kong and the British concession in Shanghai, for example. In a scenario where the US is not seen as at all likey to enter the war anytime soon, I could see the UK agreeing to sell oil to Japan, and even agreeing not to aid the Nationalist Chinese, as odious as that may be to modern tastes. The last thing the UK needed was another war, especially a war that might threaten the very resources in the empire that Britain was calling upon for the fight in Europe. As for the Dutch, of course they don't want to be puppets of Japan, but what choice do they have? The DEI is not strong enough to stand on its own, and they know it. If the US and Britain do not back their play, I think they will sell oil to Japan. If it is a choice between selling the oil for money, or having the oil taken by force, it is no choice at all.
Of course, evenything I have just said presupposes a nuetral/isolationist US. Such a US probably wouldn't embargo oil anyway. If they did, however, without seeming at all likely to actually enter the war, I do think Britain and the DEI will still sell Japan oil. That means that Japan doesn't strike south, at least, not yet. Even if they can buy all the oil they need on the world market, they are still running out of the hard currency reserves to pay for it. After that runs out, they may be forced to take what they can grab anyway. It will be enteresting, though, if the Two-Ocean Navy is already starting to come into being. I am not sure even the Japanese militarists will be crazy enough to take that on, although they may not feel like they have a choice.
Honestly, if there is a US only embargo, I think it may delay the war in the Pacific for a long while (maybe a year or two), but it is hard to see it disappear altogether. They NEED oil, they won't be able to pay for it for long (all of the old Japanese export industries that brought in currency reserves as geared towards war work by now), and the European powers are weakened.