Also, the "Pan-Malay" discourse IOTL, which basically translates into Indonesian nationalism, is the product of the long time of union of most of the Archipelago under Dutch rule with Malay/Indonesian used as the local lingua franca of the colonial empire (the Dutch were remarkably uninterested in spreading Dutch to their colonial subjects in the East Indies). Cancel that, and any "Malay" identity becomese utterly unattractive to, say, most Javanese (not that they ever indentified as such IOTL, as opposed to adopting an Indonesian identity, primarily expressed in Malay).