Hide uncategorized from widget shop

add_filter( 'get_terms', 'ts_get_subcategory_terms', 10, 3 );

	function ts_get_subcategory_terms( $terms, $taxonomies, $args ) {

		$new_terms = array();

		// if it is a product category and on the shop page

		if ( in_array( 'product_cat', $taxonomies ) && ! is_admin() &&is_shop() ) {

			foreach( $terms as $key => $term ) {

				if ( !in_array( $term->slug, array( 'uncategorized' ) ) ) { //pass the slug name here

					$new_terms[] = $term;

				}}

				$terms = $new_terms;

			}

	return $terms;

	}