Theres a whole bunch of scenario ideas in this.
A historical point people need to remember is if you want to build a single, centralised nation, then you make sure these things dont happen - language is a weapon you can use to unify a nation.
To use the example of France, which definitely did use language as a weapon to unify the Nation, "for the linguistic unity of France, the Breton language must disappear." (their culture minister in 1925. Im sure Kenji could run us through all the citations and footnotes, if we could find that darling pillar of our online community).
My feeling is that the 3I will have gone through phases of supporting linguistic uniformity to support nation building, and phases of supporting linguistic diversity. I can also imagine some fun situations where, say, the Office of Calender Compliance is trying to emphasise that there is only one Spanish language dammit, and Valenciano and Catalan and so on are dialects, while the IISS is supporting the dialects as languages because of a combination of some diversity mandate or other, and an ideology that says 'if you can think in more than one language, you can think in more than one way, and a scout who can only think in one way belongs in the Navy'.
Ian Whitchurch