Revision of custom event view slug snippet

event-view-url-slug-filter.php

<?php
/**
 * Modify the "bases" used to form event URLs for various views.
 *
 * @param array $bases
 *
 * @return array
 */
function rename_event_view_slugs( $bases ) {
	if ( isset( $bases['month'] ) ) $bases['month'] = [ 'calendar', 'calendar' ];
	if ( isset( $bases['list'] ) )  $bases['list']  = [ 'all-events', 'all-events' ];
	if ( isset( $bases['photo'] ) ) $bases['photo'] = [ 'picture-board', 'picture-board' ];
	return $bases;
}

/**
 * Wire up our code used to modify event slugs in the rewrite rules.
 */
add_filter( 'tribe_events_rewrite_base_slugs', 'rename_event_view_slugs', 20 );