There is an interesting angle that most are missing. I suspect that Trump HAS this information. Issuing it might have played to Obama’s favor. So rather than do that, Trump is pressuring Obama to release it with the Oct 31 deadline. The inference is that, “if you don't come clean I will release it for you.”
Look for the pressure to build. It puts Trump in a great position since he can always hold back. But Obama can't escape that it is out there. Trump can even find a way to now get this information out there without necessarily having his name attached to it.