Think logically.
The only scenarios that allow that kind of precise foreknowledge (putting aside time travel) -
a) he was already dead and they just delayed the announcement
b) he's not dead, just in custody.
But both would require his family to be in on the deception… why?
Because a deal was made to keep them out of trouble?
I don't buy the idea that he was tried and executed in secret.
Most people, myself included, would not go for that kind of secret justice on politicians, regardless of their crimes.