The look of language in 100 years will depend on who’s looking at the language and the perspectives and beliefs that they possess.
With the advent of social media and advanced communication technologies, some believe that language has been greatly diminished. For instance, the famous linguist and thinker Noam Chomsky has called Twitter (to name one social media platform) "very shallow communication." If social media and digital communication continues to dominate in the next century, it's likely, if one looks at language as Chomsky does, that language will look increasingly simplistic and trivial.
Another linguist might look at language differently. The linguist Gretchen McCulloch believes that the internet reflects the ever-changing nature of language. She believes that there's no "right way to communicate." Whatever language looks like in 100 years, linguistics like McCulloch appear less apt to put a value judgement on it and more inclined to think about it in terms of what this hypothetical future language says about society. Again, if society continues to be heavily reliant on digital forms of communication, it's possible the language could feature more acronyms and emojis (which, again, isn't necessarily a bad thing).
Finally, there's the possibility that in 100 years, language will look notably uniform due to censorship. Many credible journalists and writers have raised alarms about the power of tech companies to limit and extinguish certain types of language. If these tech companies remain powerful in the decades to come, language might look substantially less free and open.