As you've pointed out, the comma is the list operator.

What do you mean by that? Commas can construct lists, but only in list context. Commas in scalar context don't. Witness:

#!/usr/bin/perl

use strict;
use warnings;

sub context {
    print wantarray ? "LIST\n" : "SCALAR\n"
}

my @a = (context, context);
my $a = (context, context);

__END__
LIST
LIST
SCALAR
SCALAR
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Abigail