@fktos-tam-906n one of the most important things when redesigning is not breaking existing URLs - so you need to make sure all redirects are in place.
I have been working on Bernard, an automated broken links checker service with this exact feature: if you ever rename or remove a page and forget to set up a redirect, you'll get a notification.
This feature isn't out yet, but it's planned to release within the next few weeks. If you want you can sign up (there's a free tier) and let me know if you have any feedback. It's a very common issue, and honestly I haven't found anything good enough for my websites and clients until I started working on this problem.