Can confirm, though it's unlikely to be some piracy check. The epub just has a couple of errors that might make it difficult for Amazon's server-side epub parsing implemention:
$ epubcheck ~/Downloads/nietzsche-a-guide-for-the-perplexed-r-kevin-hill--annas-archive.epub
[...]
ERROR(RSC-005): ./Downloads/nietzsche-a-guide-for-the-perplexed-r-kevin-hill--annas-archive.epub/index_split_003.html(172,403): Error while parsing file: element "blockquote" incomplete; expected element "address", "blockquote", "del", "div", "dl", "h1", "h2", "h3", "h4", "h5", "h6", "hr", "ins", "noscript", "ns:svg", "ol", "p", "pre", "script", "table" or "ul" (with xmlns:ns="http://www.w3.org/2000/svg")
ERROR(RSC-005): ./Downloads/nietzsche-a-guide-for-the-perplexed-r-kevin-hill--annas-archive.epub/toc.ncx(62,42): Error while parsing file: playOrder sequence has gaps
Check finished with errors
Messages: 0 fatals / 69 errors / 0 warnings / 0 infos
Unfortunately I couldn't find any other epub versions. Though I just discovered the Kindle ePub fix project and converted the ePub to a fixed version using the en
language tag. That seems to work because the book just showed up in my Kindle library. :)