[WordPress] Remove Page content editor for specific template

functions.php

/**
 * Title: Remove Page content editor for specific template
 * Author: Mattias Ghodsian
 * Donate a cup of coffee: https://www.buymeacoffee.com/mattiasghodsian
 * Donate Eth: 0xBBB96204E45D11C9799c6B12E6eE6F0d4A071Ef5
 */
add_action('admin_init', 'mg_remove_editor_init');
function mg_remove_editor_init() {
    $post_id    = $_GET['post'] ? $_GET['post'] : $_POST['post_ID'] ;
    $template   = get_post_meta( $post_id, '_wp_page_template', true );
    $template   = str_replace('templates/', '', $template);

    if($template == 'landing.php'){
        remove_post_type_support('page', 'editor');
    }
}