The greatest risk of fragmentation of the English language right now comes from the various African pidgin and creoles. Africa's momentum, along with globalist Africanism, may generate some support for non-standard versions of English.
History does not stop. The French held out until 1960, 150 years after the fall of Napoleon, which is what certifies the definitive death of France as an Empire.
If we take 2016 as the end of the American Empire, with the entry of Trump's isolationism into power, the supremacy of the English language can endure until 2170. This is nothing. Our job is to bring that date forward, and leave a world prepared for the eradication of English as completely as possible.
For example, a strategic agreement between Europe, China, Russia, Ibero-America, India, the Arab world and African indigenous peoples can aim to deliver huge sums of money for the development of the most advanced machine translation platforms possible.
Deepl is a technology that was born in the European linguistic chaos, from the hand of the Germans. As I write this, I have taken my text and translated it with this technology. Not bad at all:
Translated with
www.DeepL.com/Translator (free version)