"... the same terms as Perl version X.X or higher"

That's actually a really good idea, especially with the addition of a simple "or higher at your option". The main source of the confusion was trying to figure out if authors meant follow perl's terms, perl's terms at the moment I write this, follow perl's terms at the moment I write this or any later terms at your option.

As far as the licensing/wondering issue, that's precisely what I was concerned about, the fact the legality of using the module was less clear than it probably should have been.