Prior art only applies to patents, not copyrights. The preexisting publication of copies of this poem would also undercut any such attempt.
That said, the fact that one can ONLY find copies of the work by looking to 3rd parties (rather than Oracle) should undercut any arguments they try to make against discussing it for the purpose of criticism to be fair use.
That said, the fact that one can ONLY find copies of the work by looking to 3rd parties (rather than Oracle) should undercut any arguments they try to make against discussing it for the purpose of criticism to be fair use.