It works for me; that is, (on my particular systems with the particular versions of Perl I'm using,) passing \*ARGV to a (trivial) function that expects a filehandle certainly does cause it to read the contents of all the files in @ARGV, even if I have reassigned @ARGV since the last read from <>.

So, I'm now intrigued by that "may not" there. What are the conditions where it doesn't work? Is it platform-based? version-based? phase-of-moon-based...?