That seems to be the case given the introduction they provided to their upload of NXE:

“This is a reposted work. The original creators can be found over at http://www.eyrie.net/NXE/. I claim no responsibility for this work, and just want to take advantage of AO3's download system.”

Presumably they want to convert large swaths of EPU’s output into one of the formats you’d mentioned. It seems like that would be a lot easier with some sort of software solution rather than rehosting an entire body of work on AO3, especially given the time that had to have been spent copying and pasting into their submission system. It’s pretty weird for sure, and certainly rude not to at least ask permission.

That said, it’s interesting to see the word counts for various Eyrie projects when uploaded en masse in a way that AO3 interprets as a single work. For example, Undocumented Features - uploaded as 280 seperate chapters, and presumably right up to date given that “Fable of the Reconstruction” is included - clocks in at 5,047,415 words. Which, if you use the Hugo Awards’ minimum word count requirement for the Best Novel category, 40,000 words, means that the whole of UF translates into roughly 126 short novels.

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