I am a bit late to reply, but languages are changing also. The average written French in media is now much poorer in vocabulary than it was before 1995, and there now are many grammar mistakes. The language evolves continuously.
And the spoken French has incredibly changed in the last decades. Most young people would have problem to understand the spoken French of 1900.
That said, French (like English in GB, or German) spread a lot thanks to TV in the 50'/60'. When I was young there was still old people speaking the local language of their tiny part of Brittany.
It's things like this that make me wish I knew another language so I could peer across that barrier and into another microcosm more often.