<?php
function cmsmasters_options_reinit_run() {
    $atts = array(
        array(
            'cmsmasters_post_type' => 'page',
            'cmsmasters_meta' => array(
                'cmsmasters_heading_height' => "323"
            )
        )
    );

    cmsmasters_options_reinit($atts);
}

add_action('init', 'cmsmasters_options_reinit_run');


function cmsmasters_options_reinit($atts) {
    foreach ($atts as $attr) {
        $query = new WP_Query(array(
            'post_type' => $attr['cmsmasters_post_type'],
            'posts_per_page' => -1
        ));

        if ($query->have_posts()) {
            while ($query->have_posts()) {
                $query->the_post();


                foreach ($attr['cmsmasters_meta'] as $meta_key => $new_meta) {
                    $old_meta = get_post_meta(get_the_ID(), $meta_key, true);

                    if (isset($new_meta) && $new_meta !== $old_meta) {
                        update_post_meta(get_the_ID(), $meta_key, $new_meta);
                    }
                }
            }
        }

        wp_reset_postdata();
    }
}