As usual I spoke with Solas after the Temple of Mythal, he asked me about what I was going to do with the knowledge of the Well but this time I opted for the answer "One thing at a time." ...
I was rather surprised, therefore, to get a "Solas disapproves" in response. Surely not counting one's chickens until Cory is dead would seem a wise course?
My opinion is that Solas is a planer. Many people here disagree with me on that however.
So, I believe he thinks far ahead, assuming different possible outcomes and deciding on a course of action based on his assessment. Which is why he leaves Lavellan even before the final battle. If he was more spontaneous he could stay, make a decision only when everything is settled. But he does not, he plans ahead, judges the situation, and decides to leave Lavellan long before he is actually "forced" to do so. Based on this notion it makes sense that he does not like to hear somebody say "uh, time will well". He wants to see that you have thought it all through, know exactly how to react in any given future situation.
Now, of course plan and execution are not always the same, this is not what it is about. Sometimes you plan and things go wrong or you change your mind. But the difference is if you are willing to commit (plan) or if you try to keep things open for as long as possible (spontaneity). Solas seems the former to me. And so he might think you reckless if you admit not to have a plan.
Then the speech that followed puzzled me even more. He said that I would be called upon to decide whether the Chantry continued or not. Now it has been a complaint of the anti-Chantry lobby that is something we are specifically are not able to do. We can make decision that steer who becomes next Divine, we can vote for someone or not and your approval rating with her will determine how successful her reign will be, but so far as I am aware you can never actually declare "no more Chantry". I was also puzzled why this had anything to do with the Well.
I must admit I am not sure what the dialogue was like. From what you say, maybe it was just a flaw in writing. OR Solas thinks ahead (i.e. no explicit divestiture but picking a Divine whose reign will lead to one in the longer run).
In general, everything is related to the well, which is nothing but "universal knowledge". And I think they meant to remind us that the Chantry is at the heart of all issues, which is not wrong because it is the dominating religion in most of Thedas, thus having immense power.
Then thinking it over I realised that the Well is a repository of knowledge that has been recorded since the time of the elven gods. Whilst it has been said by DG that the Maker will never be proven to exist or not (and he is of course no longer lead writer) destroying belief in the Chantry does not equate to destroying belief in the Maker.
I agree.
Next game is anticipated to take place in the north. Is part of what Solas has planned to reveal the truth about the old gods and Andraste and to bring about the end of the Chantry? Could that be why he gave his orb to Corypheus?
I don't know. I don't even try to assume his plans or future actions. Your thesis is as likely to me as any other. 