This sounds like a bad idea. You don't want private keys to a production subdomain being handed around teams. For instance, let's say you have dev.mybank.com. Somebody could trivially poison a DNS cache for a local system to redirect to their server, have a valid SSL key on the company domain, and implement a very real-looking phishing website for the company.
Our corp has corptech.com and a few similar ones for this purpose. A generic .com costs about nothing, so no point in running anything non-production on your primary domain.
Another problem - controlling a subdomain could be used to steal login cookies from the main website. This is why Github moved Github Pages to a separate domain: https://blog.github.com/2013-04-09-yummy-cookies-across-doma...