Re: the Soviet experience
I remember every Soyuz flight after Soyuz 4 and 5 .
And the mission was announced maybe after liftoff but certainly before it ended. I'm sure it was the same for every previous flight.
As for announcing before: well there was Soyuz 18 that linked with Apollo and every flight after Soyuz 25 which was a failed attempt to dock the fist time with Salyut 6.
Raoul