Hi [NAME],   Even expired support services (warranty contract), you can still download firmware updates. If the server is at its end of service life, engineering will not be releasing new firmware updates. Speaking of end of service life, there is no article stating specific dates, usually 5 years from its release date.    So to answer your question, are you permitted, yes you are. Newer versions, depends on it's EOSL on engineering release. But you still permit to download existing most recent firmware updates.    Hopefully that answers your question. 
I've got a few PowerEdge rack servers (and a Precision desktop), all of which have expired support services, and at least one of which reached the end of service life. Am I still permitted to download and install newer versions of software (i.e. BIOS, firmwares) from "Drivers & Downloads"?
Drivers & Downloads