Snippet to bulk change the auto-post template for a selection of posts

bulk-update-auto-post-template.php

<?php
function pgmb_batch_update_templates(){
	$product_ids = get_posts([
		'post_type' => 'product',
		'fields' => 'ids',
		'numberposts' => '-1',
	]);

	foreach($product_ids as $product_id){
		$product = wc_get_product($product_id);

		if(! $product instanceof \WC_Product){ continue; }

		if ( $product->is_type( 'variable' ) ){
			update_post_meta($product_id, '_pgmb_ap_template_id', 37272);
			continue;
		}
		delete_post_meta($product_id, '_pgmb_ap_template_id');
	}
}

add_action('init', 'pgmb_batch_update_templates');