Can't you pick Swahili or something instead? If you're going to try and impose a language on a rootless artificial post colonial state I feel like it ought to be one that's actually relevant to the region.
India is having a similar problem. The northern half obviously wants Hindi to be the lingua franca of the entire country, but the Dravidian south (and the weird eastern states) don't see any benefit to that and are rapidly anglicizing.
East Africa has a long history of Swahili being the language of trade, but they don't really seem to be interested in having a “native” national language, even as they grow closer into a federation in the coming years.
Rwanda in particular is a really bizarre case. Having been both a German and Belgian colony, the formerly French speaking country decided to join the British Commonwealth and make English the official language of instruction for its schools.
The people “scared” of China ever overtaking the Anglosphere probably don't have anything to worry about. We could all sabotage our countries to be Mad Maxian post-apocalyptic dystopias and all the developing countries of the world would still teach their kids English.
It's more than a little bit frustrating—obviously, this is the end result of colonizing a significant chunk of the planet, but I'm beginning to feel like my own language doesn't really belong to me anymore, if it ever did in the first place.
The decreasing percentage of native English speakers is almost certainly less than 50% at this point, and it's gotten to where cultural developments from centuries of speaking this language—the references we all know instinctively—have to be phased out to accommodate ESL speakers.
I imagine that in the coming centuries, the high dialect spoken in the “white Anglosphere” will be considered old fashioned and out of touch in comparison to the vulgar Englishes of the rest of the world. “Legal English,” like the strange version of French that developed in England after the Norman conquest, will probably emerge in whatever succeeds the EU as the language all laws are written in.
We probably wouldn't understand a word of it.
Late Roman writers described this happening around them as the language of Virgil and Caesar evolved into what is now French, Spanish, Italian, etc. I won't join them in their condemnation of languages changing, but I will say it's kind of a melancholic feeling to think about it.
I guess there's no point delaying the inevitable. Behold: an East African country united by their adoption of a West Germanic language.