Well, English is co-official with Hindi. Originally, Hindi was even supposed to be the only official language at a national level (states can have their own official languages). The Indian Constitution of 1950 declared Hindi as the sole official language, with English being used only temporarily for a 15-year transitional period. A number of politicians who pushed for this clause did see phasing out English as part of the decolonization process.
But it's true that English usage alongside Hindi as co-official has been extended indefinitely due to non-Hindi-speaking regions preferring to use English over Hindi when dealing with the central government. The Constitution was amended in 1967 to remove the phase-out period, partly in response to some riots: https://en.wikipedia.org/wiki/Anti-Hindi_agitations_of_Tamil...
But it's true that English usage alongside Hindi as co-official has been extended indefinitely due to non-Hindi-speaking regions preferring to use English over Hindi when dealing with the central government. The Constitution was amended in 1967 to remove the phase-out period, partly in response to some riots: https://en.wikipedia.org/wiki/Anti-Hindi_agitations_of_Tamil...