Some time yesterday people here were talking about how many of the questions Lavellan can give and answers Solas provides sounded an awful lot like the questions and speculations we've had in the forum, and people jokingly (and not-so-jokingly) guessed that BioWare comes into this thread to take notes of our reactions.
I've also been lurking long enough to know that a lot of what's revealed and what happens in Trespasser, many of us had already guessed. (That Solas really did seal the old gods, that his plan really is to collapse the Veil to reshape reality, that Sandal's prophecy about "the magic coming back" really is Solas' plan to collapse the Veil, that he does refuse to let Lavellan join him even if she wants to, that he does explain a bit, give her a Big Dang Kiss and then leave, that he does watch her in her dreams, etc.)
I just played the end of Trespasser again, and I noted the line where Solas says, "You have a thoughtfulness I always respected. It would be too easy to tell you too much," and thus allow the Inquisitor to figure out how to stop him.
I'm now wondering if that was a meta-nod by the devs. XD
That is, they dropped little vague hints here and there throughout the game to Solas' nature and plan, but they might have underestimated how devotedly many of Solas' fans (romanced and friendshipped) searched for clues to figure out his plan. This might be their way of saying, "Oh sh*t, we can't keep dropping hints anymore or they'll figure it out long before it happens. Even when we think we're being subtle, the fans have an obsessiveness thoughtfulness we hadn't anticipated, and it would be too easy to accidentally reveal too much."
I'm sure that wasn't their thought when they wrote that line, but if it had that would be too funny!