Filter Community Events Event Category $args

gistfile1.php

<?php
add_filter( 'tribe_community_events_event_categories', 'ce_fe_cats_order', 100 );
/**
 * Filter the $args for the event category option on the front-end form of Community Events
 */
function ce_fe_cats_order( $args ) {
	$event_cat_ids = (array) $currently_selected;

	if ( ! empty( $event->ID ) && empty( $currently_selected ) ) {
		$event_cats = wp_get_object_terms( $event->ID, TribeEvents::TAXONOMY );
		foreach ( $event_cats as $event_cat ) {
			$event_cat_ids[] = $event_cat->term_id;
		}
	} elseif ( !empty( $currently_selected ) ) {
		$args = array(
			'hide_empty' => false,
			'orderby' => 'name',
			'order' => 'ASC',
			'include' => $event_cat_ids,
		);
		$event_cats = get_terms( TribeEvents::TAXONOMY, $args );
	} else {
		$event_cats = array();
	}
	$args = array(
		'hide_empty' => false,
		'orderby' => 'name',
		'order' => 'ASC',
		'exclude' => $event_cat_ids,
	);
	// Could have used wp_terms_checklist(), but it didn't have the customizability required.
	$cats = get_terms( TribeEvents::TAXONOMY, $args );
	$cats = array_merge( $event_cats, $cats );

	return $cats;
}