In the future it's unlikely that we'll actually speak about products at all until they're ready to go to press, or we're ready to send out the digital edition ahead of sending the book to press, which is effectively the same thing. It's unfortunate because it means we won't ever be able to include you guys in the process again, but that appears to be the reality of game publishing today.
That's understandable. FWIW from my experiences from the customer side of things, it doesn't need to be an all or nothing approach. I have had positive experiences with other RPG companies where there has been an announcement and then delays, even delays of similar magnitude to those you have experienced.
It's just a question of what you do with that time. The fan proofing has already proven its value with the MAG. I hope you don't drop this idea completely. It would seem like cutting off your nose to spite face. Other things might be of value too, provided that they are managed well.