"Can anyone point me toward resources for unshortening t.co links in Perl? WWW::Shorten doesn't include it.

It does, the makealongerlink method, illustrated in the Synopsis

Update: disregard the above.

#!/usr/bin/perl
use strict;
use warnings;
use LWP::UserAgent;
use feature 'say';
my $url = 'https://t.co/O4qjsxuCsV';
# pretend to be a proper browser
my $uaname = 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (
+ KHTML, like Gecko) Chrome/40.0.2214.93 Safari/537.36';
my $ua = LWP::UserAgent->new;
$ua->agent( $uaname );
my $resp = $ua->get($url);
say $resp->header('title');
[download]

returns:

https://www.malaysia-chronicle.com/?p=225241
[download]