Society which is by default quite lazy and/or greedy, would see it as to bothersome to change the language. (companies and the countries would also have to invest a ton of money in changing documents and street signs and whatnot)
I mean lets say you mix up the germanic parts of english with french to create a new language frenglish. (it will still be quite like english since you replaced stuff like language with langue or change with change etc... while you kept stuff like house, finger, shirt etc..)
But the difference would be huge enough to bother most people. I mean Shakespeare english is like another language to alot of people and thats basically english lol.
So you either have to translate everything that is out there so new generations have use for it or you will be forced to be bilingual for a long time or you wait for the "language merge" until google translate is perfected and the process of translation will be automated.
What will likely happen is that countries with similar dialects or "languages" like dutch and german and spanish and portoguese or polish and czech will merge their languages. In this case it will not be too hard to understand the "ancient" books and files etc. our ancestors left for us.
P.s anything would have been so easy by now if germany had won WW2 xD at least in europe
