Do we need both the tags? To me, it seems that history includes language-evolution, since the history of a language is its evolution in the time. Between the two, I would prefer language-evolution to avoid the tag is used when the question asks about historical reasons, for example.
Although arguably language-evolution is a subset of history, I don’t think the reverse is always true and merging them all into language-evolution would be a mistake. For example “What is the origin of the Esperanto green star?” is not about language evolution but it does have the history tag. There could also be interesting questions about the persecution of Esperanto during the wars which would be nice for the history tag.
I would be in favour of just keeping the two tags as they are.
- Rename/Deplace history since it is unclear; I thought it was about historical facts about Esperantujo. If we have to keep it, I suggest language-history
- Keep language-evolution. The history of Esperanto is not only its evolution. Many words appeared in an artificial way before the language "evolved".
- I would be for replacing history with language-origin (the origin of the choices of Zamenhof ktp) or language-evolution whenever possible.