Yeah I agree. Speaking of Indonesia and Malaysia, a world without a WWII would be very different. One possibility is Malaysia and Indonesia never forming together, instead we would get states like Sarawak and Sabah forming a nation while Malaya forms another nation, while Aceh and Indonesian Papua would also want out from Javan domination.
I don't know if all these independence movements could pan out, but it would be interesting to look into it.
Clearly depended on what the Indonesian (or Indies) Nationalists managed to do, tbh. The Javanese-led Nationalist Movement actually relented to have Common Malay adopted into Indonesian Language in 1928 since it use was far more widespread than Javanese.
If they managed to get Aceh and Papuan intellectuals in their circle, there would be a strong pan-Indonesian (or at least Pan-Indies) sentiment like OTL 1945-1949 espoused by Aceh ulemas (who got recruited by Japan in the Occupation), or Papuans such as Markus Kaisiepo and Marthen Indey who was working together with (ex-Digoel convicts) Indonesian Nationalists. But if the Dutch nipped them in the bud and outright separates Papua as its own territory (5th Part of the Empire) with its own educational system, then the Indonesians can't do anything about annexing them since they (especially the Western-educated ones like like Mohammad Hatta and Soetan Sjahrir) respected
Uti Possidetis Juri. There was also two strong political movements within the Central Mollucas and Minahasan Peninsula for them to be added as a proper Dutch provinces since both of them enjoyed pretty high standards of life and also far more culturally assimilated compared to the rest of the Dutch East Indies.
Establishing a puppet state which respected their cultural autonomy like the actual aims of
Konfrontasi is still a possibility, though, but it's for the 50s/60s stuffs. OTL Vorstenlanden (Yogyakarta and Surakarta monarchies) only managed to remained exist within the Republic until now because its rulers proclaimed their loyalty to the Republic first rather than waiting to be subdued by the Indoensian nationalists youths.
Besides all of that, i'm actually very intrigued with the parallel development of both
Indies Nationalism (emerged in 1911 by Ernest Douwes Dekker, which advocates for a common equality regardless of race and religion as long as you are loyal to the Indies homeland, empashizing shared Indies identity to unite the nation, and demanding independence from the Netherlands),
Indies Commonwealth movement (emerged in 1917 by Hubertus van Mook, which advocates for a self-government for East Indies, respecting cultural differences and espousing cooperation, and to have an equal standing with other parts within the Kingdom of the Netherlands), and successor of the aforementioned Indies Nationalism,
Indonesian Nationalism (emerged in 1924 by Soekarno, a pupil of Douwes Dekker, which is a bit more strict regarding who is considered as natives, also more empashizing on cultural uniformity between the existing natives, and outright demands independence from the Dutch).
The Commonwealth proposal initially have the upper hand because of their all-encompassing nature, but when Colijn, Welter, and other Dutch conservatives and reactionaries aren't willing to gave an inch for the Indies autonomy throughout 1936-1941, the Indonesian Nationalists won, especially after the Japanese knocked down the colonial government.
Edit: A massive one to correct which one is which regarding the three self-governmental movements in the Dutch East Indies. Ernest DD advocates for independence since the start unlike Van Mook which aimed for a Commonwealth. Pinged
@L'amateur d'aéroplanes,
@KaiserKatze,
@Strategos' Risk,
@Quinkana, and
@Carlos I de Quito since i did not want to create a wrong impression.