Hide the Featured Image on Selected Posts

add_action( 'init', function () {
    register_post_meta( '', '_wpide_hide_thumbnail', array(
        'type'          => 'boolean',
        'single'        => true,
        'default'       => false,
        'show_in_rest'  => true,
        'auth_callback' => function ( $allowed, $key, $post_id ) {
            return current_user_can( 'edit_post', $post_id );
        },
    ) );
} );

$wpide_hide_thumb_here = function ( $post_id ) {
    // Only on the post's own page, so archives and related posts keep the image.
    return is_singular() && (int) $post_id === get_queried_object_id() && get_post_meta( $post_id, '_wpide_hide_thumbnail', true );
};

add_filter( 'post_thumbnail_html', function ( $html, $post_id ) use ( $wpide_hide_thumb_here ) {
    return $wpide_hide_thumb_here( $post_id ) && in_the_loop() ? '' : $html;
}, 10, 2 );

add_filter( 'render_block_core/post-featured-image', function ( $content, $block, $instance ) use ( $wpide_hide_thumb_here ) {
    $post_id = isset( $instance->context['postId'] ) ? (int) $instance->context['postId'] : get_the_ID();
    return $wpide_hide_thumb_here( $post_id ) ? '' : $content;
}, 10, 3 );

add_action( 'enqueue_block_editor_assets', function () {
    $screen = get_current_screen();
    if ( ! $screen || 'post' !== $screen->base || ! post_type_supports( $screen->post_type, 'thumbnail' ) ) {
        return;
    }

    wp_register_script( 'wpide-hide-thumb', false, array( 'wp-plugins', 'wp-element', 'wp-components', 'wp-data', 'wp-editor' ), '1.0', true );
    wp_enqueue_script( 'wpide-hide-thumb' );
    wp_add_inline_script( 'wpide-hide-thumb', <<<'JS'
( function ( wp ) {
    var el = wp.element.createElement;
    var Panel = ( wp.editor && wp.editor.PluginPostStatusInfo ) || ( wp.editPost && wp.editPost.PluginPostStatusInfo );
    if ( ! Panel ) { return; }

    function HideThumb() {
        var hidden = wp.data.useSelect( function ( select ) { return !! ( select( 'core/editor' ).getEditedPostAttribute( 'meta' ) || {} )._wpide_hide_thumbnail; }, [] );
        var editPost = wp.data.useDispatch( 'core/editor' ).editPost;
        return el( Panel, null,
            el( wp.components.CheckboxControl, {
                label: 'Hide featured image on this post',
                checked: hidden,
                onChange: function ( value ) { editPost( { meta: { _wpide_hide_thumbnail: value } } ); }
            } )
        );
    }

    wp.plugins.registerPlugin( 'wpide-hide-thumb', { render: HideThumb } );
} )( window.wp );
JS
    );
} );