Would a successful anticolonial uprising combined with an earlier end to scientific racism help?
And the populous Asian/African former colonies where creoles might have (or in the case of Nigeria, have formed) either use colonizer languages or native ones for formal purposes.The problem with the idea of creoles gaining official status is that the languages of the colonizers remain prestigious and useful. Even the Haitian Creole that gained official status two centuries ago after a successful revolution, the language of ten million people, has to share status with French; even Sranan Tongo remains relatively marginalized in Surinam, notwithstanding the relatively minor importance of Dutch on the world stage; even Jamaican Creole is far from challenging English, notwithstanding a globally influential pop culture.
Supplanting them may be impossible, but some sort of defacto equilibrium (certainly not dejure) as with Singlish isn'tFor this to work, I think you might need a two-step process, with the creole society making a complete break with the colonizer and with the colonizer's language going into eclipse. The situations in Haiti and Surinam seem to come closest to this scenario, but even there, ties with the former metropole remain importance. Creoles related to English and French and Portuguese, meanwhile, have to compete directly with those world languages. Even ones with very large numbers of speaker face intense pressure.
The problem with this is the framing of the question. Creoles are just a member of the same dialect continuum as their parent language, but languages aren't surrounded by insurmountable barriers except those formed by nationalism. If you know Jamaican Creole or Naija, it's relatively effortless to learn standard English, and it's much easier for schools to teach standard English than it would be to develop a standard written form that everyone in Jamaica or Nigeria could agree on. In the case of non-settler colonies like Nigeria, a hypothetical standardized form of Naija, even if one existed, wouldn't actually be worth learning compared to the benefits of learning English. It doesn't make creoles not a valid language just because it's easy to teach creole speakers the parent dialect in school, but there's no particular reason to try to flash back to the 19th century and develop constructed ethnolinguistic identities like Finnish and Bulgarian.