This could not be more wrong. Meta is still using PHP AFAIK but I'm not sure it's modern. They created the Hack programming language ~10 years ago but it doesn't look like it's been updated in several years. Most of the improvements they touted were included in PHP 7 years ago.
Brian Krebs is a saint for being the perennial punching bag and target of cybercriminals but continuing to publish important information independently.
Laravel 3 and Laravel 4 were released in ~2012. The upgrade from Laravel 4 to 5 (released Oct 2013) is probably the biggest hurdle, but you can likely upgrade from Laravel 5 to Laravel 12 in a week or sooner with Laravel Shift.