嗯，我在回答我的问题。

正如@MilanPetrovic在评论中提到的，这很容易做到。只需创建短代码并检查用户是否购买了特定的产品。

代码如下：

/**
 * [wcr_shortcode description]
 * @param  array  pid    product id from short code
 * @return content          shortcode content if user bought product
 */
function wcr_shortcode($atts = [], $content = null, $tag = \'\')
{
    // normalize attribute keys, lowercase
    $atts = array_change_key_case((array) $atts, CASE_LOWER);

    // start output
    $o = \'\';

    // start box
    $o .= \'<div class="wcr-box">\';

    $current_user = wp_get_current_user();

    if ( current_user_can(\'administrator\') || wc_customer_bought_product($current_user->email, $current_user->ID, $atts[\'pid\'])) {
        // enclosing tags
        if (!is_null($content)) {
            // secure output by executing the_content filter hook on $content
            $o .= apply_filters(\'the_content\', $content);
        }

    } else {
        // User doesn\'t bought this product and not an administator
    }
    // end box
    $o .= \'</div>\';

    // return output
    return $o;
}

add_shortcode(\'wcr\', \'wcr_shortcode\');

[wcr pid="72"]
 This content only show for users that bought product with the id #72
[/wcr]