I am not a linguist but you are using "evolution" as having another meaning than LilleSvin. For you it is something which is positively improving as in the layman idea about Darwin's evolution theory and for LilleSvin "evolution" means exactly what it means in biology: Changes that are at a wide scale.
For example in old Norse that was used on the north and east coasts of UK in 900 CE, "time" was not pronounced like "ta-ii-me" and the English word for "ship" was pronounced "skip", the more modern pronunciation happened after the great vocalic change, an evolution of the spoken dialect. There is nothing positive or negative in the great vocalic change, but it is an evolution of the language because after some time, most people spoke it that way, not anymore like old vikings did.
(edited because I made many spelling errors)