Probably not with the current tech, but there are lots of ways to do it. You don't need to delay the signal, only the information tied to that signal. If you get away from static identifiers and use something like a rotating RSA key, then the data associated with that key could be released at a later time. Not ideal for transparency unless there's a strict retention/audit process for the gold copy (perhaps one of the few legit use cases for immutable block chain since all identifies should be unique too).