Allow for changing sub domains and preserving old URL's

My company is rebranding. We have our site hosted on olddomain.huducloud.com . We have many articles published with a public link. Our company is rebranding so we would like to change the domain to newdomain.huducloud.com . Support says they can do this but that old shared URL's to articles will no longer work. In cases where the company needs to change their domain please make the old domain and alias that redirects to the new domain so old URL's are preserved.