Feed Google News para WordPress. Esse código adiciona um novo endpoint de feed no seu blog WordPress. Esse endpoint é cadastrado no functions.php com a url /feed/google-news e /rss/google-news. Valide seu feed via Google Search Console.

functions.php

<?php
// Custom RSS Feed following Google News specification
// No Products Allowed in This Feed

add_action('init', 'googleNewsRSS');
function googleNewsRSS(){
    add_feed('google-news', 'googleNewsRSSFunc');
}

function googleNewsRSSFunc(){
    get_template_part('rss', 'google-news');
}

function the_content_feed_for_google_news($content) {
    return $content;
}

rss-google-news.php

<?php
/**
 * Template Name: Custom RSS Template - Google News
 */
$query_posts_args = array(
    'posts_per_page' => 14,
    'orderby' => 'modified',
    'order' => 'DESC'
);

$posts = query_posts($query_posts_args);
header('Content-Type: '.feed_content_type('rss-http').'; charset='.get_option('blog_charset'), true);
echo '<?xml version="1.0" encoding="'.get_option('blog_charset').'"?'.'>';
?>
<rss version="2.0"
     xmlns:dc="http://purl.org/dc/elements/1.1/"
     xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
     xmlns:admin="http://webns.net/mvcb/"
     xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
     xmlns:content="http://purl.org/rss/1.0/modules/content/">
    <channel>
        <title><?php bloginfo_rss('name'); ?></title>
        <link><?php bloginfo_rss('url') ?></link>
        <description><?php bloginfo_rss('description') ?></description>
        <lastBuildDate><?php echo mysql2date('D, d M Y H:i:s +0000', get_lastpostmodified('GMT'), false); ?></lastBuildDate>
        <dc:language>pt-BR</dc:language>
        <dc:date><?php echo mysql2date('Y-m-d\TH:i:s-00:00', get_lastpostmodified('GMT'), false); ?></dc:date>
        <sy:updatePeriod><?php echo apply_filters( 'rss_update_period', 'hourly' ); ?></sy:updatePeriod>
        <sy:updateFrequency><?php echo apply_filters( 'rss_update_frequency', '1' ); ?></sy:updateFrequency>
        <?php while(have_posts()) : the_post(); ?>
            <item>
                <title><?php the_title_rss(); ?></title>
                <link><?php the_permalink_rss(); ?></link>
                <comments><?php comments_link_feed(); ?></comments>
                <pubDate><?php echo mysql2date('D, d M Y H:i:s +0000', get_post_time('Y-m-d H:i:s', true), false); ?></pubDate>
                <dc:creator><![CDATA[<?php the_author(); ?>]]></dc:creator>
                <?php the_category_rss(); ?>
                <guid isPermaLink="false"><?php the_guid(); ?></guid>
                <content:encoded><![CDATA[<?php echo the_content_feed_for_google_news(get_the_content_feed()) ?>]]></content:encoded>
                <?php rss_enclosure(); ?>
            </item>
        <?php endwhile; ?>
    </channel>
</rss>