The same as what? A professionally recorded piece with rehearsed, trained actors under a single, focused director? Should it actually not be allowed to exist in a reversed or mixed form?!Imagine a work such as Ibsen's "The Dollhouse" with reversed gender casting - it wouldn't sound the same at all.
archive.org will accept recordings from anyone, so if someone wanted to recruit in the Volunteers: Other Projects forum for accent-specific parts for a particular recording, that'd be fine by me, but it would NOT be a LibriVox recording in my ears and wouldn't go in our catalogue.