This is an excellent analysis.

IIRC, these critical editions were published in part because of recurring questions about Anne’s authorship specifically from Holocaust deniers. Again, if memory serves, there is a big section describing the independent analysis of the paper, ink and the cloth cover of the diary to prove that they were manufactured in the correct timeframe, graphological analysis of Anne’s handwriting etc.

It was interesting to see the “raw” entries, Anne’s revision of them in view of publishing them after the war, and the further polishing and editing done by her father. He cut some things he thought were too personal and toned down some of Anne’s snarky commentary.

To me there has never been any question of her authorship. But the edition that everyone reads does sound quite polished for a girl in her early teens, intelligent and talented though Anne was. That’s because what’s being read is not a verbatim transcription of her original diary entries. The critical edition shows you Anne’s unpolished diary entries, the changes Anne made in her revision, and what her father changed later. It’s quite interesting from a literary history standpoint, but for a casual reader it’s probably overkill.