Use register_taxonomy_args to rename a taxonomy.

filter_taxonomy_labels.php

<?php
/**
 * Filter the Genre taxonomy and relabel as "Format"
 *
 * @author Chris Reynolds
 * @link   https://wordpress.org/support/topic/small-custom-change/
 * @uses   register_taxonomy_args 
 * @link   https://developer.wordpress.org/reference/hooks/register_taxonomy_args/
 */
function wp_support_rename_genre_taxonomy( $args, $taxonomy_name ) {
	if ( $taxonomy === 'genre' ) {
		$labels = array(
			'name'                      => __( 'Format', 'yourtextdomain' ),
			'singular_name'             => __( 'Format', 'yourtextdomain' ),
			'search_items'              => __( 'Search Formats', 'yourtextdomain' ),
			'popular_items'             => __( 'Popular Formats', 'yourtextdomain' ),
			'all_items'                 => __( 'All Formats', 'yourtextdomain' ),
			'edit_item'                 => __( 'Edit Format', 'yourtextdomain' ),
			'update_item'               => __( 'Update Format', 'yourtextdomain' ),
			'add_new_item'              => __( 'Add New Format', 'yourtextdomain' ),
			'new_item_name'             => __( 'New Format Name', 'yourtextdomain' ),
			'separate_items_ith_commas' => __( 'Separate formats with commas', 'yourtextdomain' ),
			'add_or_remove_items'       => __( 'Add or remove formats', 'yourtextdomain' ),
			'choose_from_most_used'     => __( 'Choose from the most used formats', 'yourtextdomain' ),
			'not_found'                 => __( 'No formats found', 'yourtextdomain' ),
			'menu_name'                 => __( 'Formats', 'yourtextdomain' )
		);
		
		$args['labels'] = $labels;
	}
	
	return $args;
}
add_filter( 'register_taxonomy_args', 'wp_support_rename_genre_taxonomy', 10, 2 );