In 2050, I think, the amount of English speakers will increase.
But it would not be native speakers – it will be a lot of people from all over the world, who will study English as a second language for building their career.
They will resemble the nobles in Russian Empire, who used French oftener, than their native Russian.
Gradually, English will play the same role as Latin played in medieval Europe or Koine (Ancient Greek) in Hellenism era in Mediterranean.
Latin was a language of Church and Science all over the west world.
English will be the language of IT and business in all over the world.
If connection between English-speaking countries will break, could commence the process of dividing English into some different languages.
That was in the medieval Europe after crushing of the Roman Empire.
Relations between regions of former Empire weren’t supported any more, and in every separate region language was being developed in its own separate way.
As a result we have the Romanic language family.
If something similar will happen with English, we will have an Englic language family.