I agree with everything you said, but I recently saw the scene again on Facebook and Geordi explains to all of them that the saucer wasn't left behind because of the Prime Directive.As its former captain, and high ranking officer in the Fleet, I am sure that he was aware that they removed the saucer from the planet, but never dreamed that it would be rebuilt.
I mean, you would need to be Geordi to do that. He had the position of Commadore, and was in charge of the fleet museum. He could sell the concept to the brass to let him piece together the ship that saved the Federation on multiple occasions for it. He would have plenty of parts and pieces from the wreckages and remnants of the Dominion War. Remember in that war, they would base attack wings around Galaxy class ships as their command/heavy hitter, so they were pumping out a lot of the War variant of that ship for several years. All of those ships gave him an option to get a replacement for the Star drive section.
Not too mention It had to be Geordi to do it, as he was one of the few Engineers that could actually rebuild the Enterprise D.
And it had to be Geordi to do it, as he would be one of the handful of people that would want to sink all of this time and effort into rebuilding the Enterprise D.
And plus Picard was out of Star Fleet for a decade so he was probably out of the loop. Riker and Troi were trying to keep their son alive, and were also out of the loop. Beverly was hiding Jack from the galaxy. Data was dead, and Worf was somehow losing the Enterprise E, to no fault of his own. Really, Worf might have known about it, but the rest of them, I doubt it.
Out of universe I have been in discussion various times over the years about it and I cannot say that I KNEW they were going to have to retrieve it, but given what we know NOW, the senior staff of the ship all knew immediately and they were all in Starfleet for a long time after. They would have heard the news or perhaps even been in attendance when it was done.
It is possible that Picard would have thought it was a total loss, but wouldn't there have been news stories about the recovery that would've come up in their browsers that would've said it was retrieved largely intact? And do they all know there is a museum where NX-01, Enterprise-A, and the Bounty are all kept and wouldn't they have hoped that in some way their ship could get there?