This has been greatly discussed in german media like a couple of weeks ago.
No, it hasn't been. I am aware of the Cicero story, but forgery of documents was never even an accusation that was made in that context, so that can't be it.
Essentially, the ministry misquoted power companies statements of the future use of nuclear plants. The choice of words and leaving out parts (or even that selective choice of text) might turn a statement by 180 degrees.
That is not forgery of documents (Urkundenfälschung). Forgery of documents is a crime, specifically the crime of presenting a document as being authored or signed in the form presented by an entity that did not in fact author or sign that document as presented. Authoring a document and putting into it an incorrect or misleading quote of some other party's statement is not document forgery, and also not a crime in itself.
AFAIR their statement went from "due to the scheduled going dark process, revision work and recertification will be needed to keep the plants running" to a statement by the ministry like "the industry said it's not possible to keep the plants running".
Which is IMHO a blatant lie.
First of all, this is all about contents of internal documents of the government, so it is kinda misleading to say "statement by the ministry". Mind you, Cicero had to sue to force the ministry to hand over the documents. Primarily, this is about documents prepared by the ministry for consumption by the minister. In this case, the document apparently was also shared with another ministry (authored in the Bundesministerium für Wirtschaft und Klimaschutz, shared with Bundesumweltministerium, because the latter is responsible for nuclear safety, both led by green ministers, with the documents being edited by people within the ministry who were essentially hired by the minister).
And also, my understanding is that the changes that were made in the editing process that apparently were the basis for the accusation made by Cicero were completely trivial and in no way made the text misleading. Actually, it seems almost as if the whole basis for the accusation is a misunderstading of the original text by Cicero. With the "text" being changed also apparently being primarily a heading.
Nähere Informationen auf Deutsch:
https://www.cicero.de/themen/atomausstieg
I think this analysis of the case is worth a read:
https://www.volksverpetzer.de/faktencheck/habeck-rechte-pseudo-skandal-akw-files/