Hostname changes affecting DNS

I have a project to change the hostnames of 40 cisco switches. My plan was to coordinate the name changes with the DNS server admins so that no DNS issues would arise. Management wants the names changed and 2 weeks later the DNS updated with the new names. They cite that the IP address are not being changed and are currently in DNS so therefore access to the devices will not be lost. I took a stance that network management tools and DNS would be affected. Are there any DNS issues caused by changing hostnames without updating DNS that can validate my stance?