You're right!

use Attribute::Handlers;

sub foreach :ATTR {
  print "Just another Perl hacker,\n";
}

sub foo :foreach {}

foo();
[download]

prints the expected, while

use Attribute::Handlers;
sub for :ATTR {
  print "Just another Perl hacker,\n";
}
sub foo :for {}
foo();
[download]

does not. I'll follow my own advice and send a perlbug.