WordPress at a glance
filter is not described

filter_block_editor_meta_boxes filter-hook . WP 5.0.0

Fires right before the meta boxes are rendered.

This allows for the filtering of meta box data, that should already be present by this point. Do not use as a means of adding meta box data.

Usage

add_filter( 'filter_block_editor_meta_boxes', 'filter_function_name_2794' );
function filter_function_name_2794( $wp_meta_boxes ){
	// filter...

	return $wp_meta_boxes;
}
$wp_meta_boxes(array)
Global meta box state.

Where the hook is called

the_block_editor_meta_boxes()
wp-admin/includes/post.php 2081
$wp_meta_boxes = apply_filters( 'filter_block_editor_meta_boxes', $wp_meta_boxes );

Where the hook is used (in WP core)

Does not used.