In reference to this question and this second question:
Is it On-topic to ask questions on the history of German language?
The list of history questions is quite long already. But are these questions about the German Language or are they about Linguistic history? or about a sociological impact of the German Language seen in a historical context?
And if they are on such impacts, are they not better suited for History.SE or Linguistics.SE?
Well, this site is about "German language & usage" but it does not state that it must be contemporary German. And any reform is related to the language and its use.
That said, it's likely a little difficult to answer questions about things in the past. Most of us will still remember the most recent reform but I'm sure none of us experienced any prior reforms. That is, only those who studied the history of the German language will be able to answer such a question properly. Therefore, you might be more successful in getting satisfying answers if you ask any questions like those on our sister-site about linguistics as I assume that there are more 'experts' when it comes to history. I'm not sure if they define those questions off-topic though.
However, this does not make a question off-topic on GLU as long as we do not expressly exclude those per definition. And I think we shouldn't go so far. Perhaps such a question will lead some experts from linguistics over to GLU some time.
A lot of these questions are in German, which is to say that they would not "fly" on other, English language site.
And other posts tagged with "History," are really about the history of a German phrase or usage, and as such, are more language questions than mainstream history.
Questions on history or on general linguistics may get better answers on our sister sites. This is not true for questions specifically asking for the history of the German language.
Language development over time is closely related to history so there will always be some unavoidable overlap but as soon as the emphasis is on language there is no reason to believe they are not on topic here. In fact sometimes the history of a word or a phrase is of great help to understand its usage, meaning, or spelling.
In summary: yes, questions on the history of the German language are welcome here.
