Not in such language, but it's absolutely the case that large companies can have emails come from the very top that include language like "subject to disciplinary action and possible termination" for failing to do some required thing. Sometimes it's phrased as "corrective action up to and including termination." It's normal in that this is something that shouldn't throw one for a loop (and in my experience the calls to action have more to do with regulation compliance than any how-to-do-your-job mandate) but it's not very frequent. Such language is usually limited to appearing in an employee handbook or conduct guide that everyone is supposed to have read and agreed to which spells out repercussions for behavior against such or other misconduct.
