I have had no proper sleep since Tuesday night, so the prophesies are coming easily today.
Once Voltronese has become the universal language and has drastically reduced the variety of souls on the planet, we will see various splinter groups appear.
Youths, responding to ever-faster development in technology and online virtual reality games, will introduce new slang terms at a rate that terrifies the original Voltron generation. Reactionary organisations called things like the Society for the Protection of Proper Voltronese (or, in Voltronese, the Puretalk Voltron Massiv) will be formed, demanding that all lingo should be limited to the official Voltron Grammar and Vocabulary as laid down in the ultimate authority, Wikipedia. These organisations will sprout terrorist extremes.
Scientific leaps will mean that everybody is medically immortal, so age ceases to be a factor. National and religious boundaries will have evaporated as globalisation, reinforced by the dominance of the Voltronese tongue, turns the world into a monoculture. The only thing that divides people will be the strictness of their adherence to the Wikipedia Voltronese. The Third World War will be fought over whether Shakespeare was the original Voltron.
In the rubble of the nuclear aftermath, rambling survivors will discover tiny clandestine pockets of rudimentary civilisation. Here, crude aboriginal languages are still spoken. Welsh, for example.