Yeah, read one sentence further than what you quoted :)

Vigenères did write about more than what universities teach as "THE Vigenère cipher". Including some vague (common for the time period) stuff about the length of substitution blocks, length of cleartext, length of what we would now call secret key.

In my book it doesn't really matter tho. He was basically there in my view. No need to split hairs.

Edit: There is also a lot of creative stuff from both world wars about symmetric encryption with throwaway-keys. In my view these approaches are also basically there. They just haven't haven't written it explicitly in a generalized manner.