@Shayne, first thing that is wrong about your code is that it is using single quotes (') instead of double quotes ("), which is said to be used:

Note the use of double quotes instead of single quotes. You must use double quotes when executing PHP functions from within WP All Import. You can’t use single quotes.

link

I asked Claude.ai to improve your code snippet from ChatGPT and it came with the following, which I managed to get working:

function update_wpbakery_image_ids($post_id, $xml_node, $is_update) {
    // Get the post content
    $content = get_post_field("post_content", $post_id);
    
    // Skip if no content
    if (empty($content)) {
        return;
    }
    
    // Array of WP Bakery shortcodes that contain image IDs
    $shortcode_patterns = array(
        "vc_single_image" => "/\[vc_single_image[^\]]*image=\"(\d+)\"/",
        "vc_gallery" => "/\[vc_gallery[^\]]*images=\"([^\"]+)\"/"
    );
    
    $modified = false;
    
    foreach ($shortcode_patterns as $shortcode => $pattern) {
        preg_match_all($pattern, $content, $matches);
        
        if (!empty($matches[1])) {
            foreach ($matches[1] as $old_ids) {
                // Handle both single IDs and comma-separated lists
                $old_id_array = explode(",", $old_ids);
                $new_id_array = array();
                
                foreach ($old_id_array as $old_id) {
                    $old_id = trim($old_id);
                    
                    // Get the attachment URL for the old ID
                    $old_attachment_url = wp_get_attachment_url($old_id);
                    
                    if ($old_attachment_url) {
                        // Try to find the new attachment ID based on the same filename
                        $filename = basename($old_attachment_url);
                        $new_attachment = get_posts(array(
                            "post_type" => "attachment",
                            "post_status" => "inherit",
                            "fields" => "ids",
                            "meta_query" => array(
                                array(
                                    "value" => $filename,
                                    "compare" => "LIKE",
                                    "key" => "_wp_attached_file"
                                )
                            )
                        ));
                        
                        if (!empty($new_attachment)) {
                            $new_id = $new_attachment[0];
                            $new_id_array[] = $new_id;
                            
                            // Replace in content based on shortcode type
                            if ($shortcode === "vc_single_image") {
                                $content = preg_replace(
                                    "/(\[vc_single_image[^\]]*image=\")" . $old_id . "\"/",
                                    "$1" . $new_id . "\"",
                                    $content
                                );
                            } elseif ($shortcode === "vc_gallery") {
                                $old_ids_pattern = preg_quote($old_ids, "/");
                                $new_ids = implode(",", $new_id_array);
                                $content = preg_replace(
                                    "/(\[vc_gallery[^\]]*images=\")" . $old_ids_pattern . "\"/",
                                    "$1" . $new_ids . "\"",
                                    $content
                                );
                            }
                            
                            $modified = true;
                        }
                    }
                }
            }
        }
    }
    
    // Update post content if modifications were made
    if ($modified) {
        wp_update_post(array(
            "ID" => $post_id,
            "post_content" => $content
        ));
        
        // Clear any caches
        clean_post_cache($post_id);
    }
}

I added this function to the Function Editor which is available from within the WP All Import Pro process.