Postponing the release 1 day in advance? This is rather unprofessional.
but implies urgency, so hints that the reasons probably arent their fault so it was delay it or have a failed release. So im sure its just some problem needing fix and in a week theyll have fixed and then no worries right?
The unprofessional thing would be to ignore the problem and release it on time even if it didnt work, surely its a more professional thing to hold it off a week until whatever hiccup caused the hold has been remedied.