No, while(<>) does not create a newly scoped $_.

Behold:

require 5.6.1;
use strict;
use warnings;

my @array= (1,2,3,4,5);
foo()  foreach  (@array);
print "@array\n";

sub foo
 {
 while (<DATA>) { return }
 # silly, but makes a small example with little input.
 }

__DATA__
clobbered
clobbered
clobbered
clobbered
clobbered
[download]