I can understand why the government would want to do away with the colonial language. It’s a reminder of a dark time. However, the decision of what the official language(s) should be can lead to some tricky politics. If one local language is elevated, it gives an advantage to those who grew up speaking it. This is especially hard for minority languages from indigenous peoples.
An example of this is in Botswana, where I’m currently living. The Tswana people came up from South Africa and displaced indigenous populations like the San and Herero. After independence in 1966 from being a British protectorate, they made English the official language and Setswana the national language. English is used in education and government, but everyone is also expected to learn Setswana to function in society. For those who didn’t grow up speaking Setswana or who don’t learn it, it’s harder or impossible to get good healthcare or a good job.
Language politics can get really messy when there are lots of local languages. I worry about what might happen as a result of this decision.